CN102377687B - Mail sending method, system and device by aiming at mailbox overflow - Google Patents

Abstract

The invention discloses a mail sending method for mail overflow, which is used to solve the problem in the prior art that when there is a mailbox overflow, because the user cannot receive mail sent by other users, the user receives information missing. In this method, when the mailbox overflows and the user mail is returned, the returned mail is cached, and the mobile terminal corresponding to the user mailbox is instructed to prompt the user to clean up the mailbox. When the available capacity of the user mailbox is not less than the returned mail contains Resend the cached message to the user mailbox when the number of bytes is set. The invention also discloses a mail sending system and device for mail overflow. As in the solution proposed by the present invention, since the returned mail is cached and the user is prompted to clean up the user mailbox, as long as the available capacity of the user mailbox is not less than the number of bytes contained in the returned mail, the cached mail will be sent to the user Mailbox, thus avoiding the omission of information received by users.

Description

A mail sending method, system and device for mailbox overflow

technical field

The present invention relates to the technical field of intelligent terminals, in particular to a method, system and device for sending emails aimed at overflowing mailboxes.

Background technique

In the prior art, when a user registers a mailbox through a mail server, the mail server will locally allocate a certain amount of storage space for the registered user, for example, the capacity of the storage space allocated to each user is 100MB. No matter how large the storage space allocated to the user is, when the user receives emails frequently, the storage space allocated to the user in the mail server will also be fully occupied.

When the storage space allocated by the user in the mail server is full, and other users send mail to the user, because the storage space allocated to the user does not have enough space to receive the sent mail, the mail server will Return the sent mail to other users, that is, the problem of mailbox overflow occurs. Currently, if other users do not resend the email to the user after the user's allocated storage space is cleared, the user will not be able to receive emails sent by other users, resulting in omission of information received by the user.

Contents of the invention

In view of this, the embodiments of the present invention provide a mail sending method, system and device for mailbox overflow, which is used to solve the problem that users cannot receive mail sent by other users when there is mailbox overflow in the prior art. The problem of missing information is received.

An embodiment of the present invention provides a mailbox overflow mail sending method, comprising:

Caching mail bounces from user mailboxes; and

Instructing the mobile terminal corresponding to the user mailbox to prompt the user to clean up the mailbox;

When it is determined that the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, the cached mail is sent to the user's mailbox.

An embodiment of the present invention provides a mailbox overflow mail sending system, including:

The mail server is used to cache mails returned by the user's mailbox, instruct the mobile terminal corresponding to the user's mailbox to prompt the user to clean up the mailbox, and determine that the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail , send the cached mail to the user mailbox;

The mobile terminal is configured to receive information prompting the user to clean up emails, and prompt the user for the information.

An embodiment of the present invention provides a mail sending device for mail overflow, including:

The caching module is used to cache mails returned by user mailboxes;

A control module, configured to instruct the mobile terminal corresponding to the user mailbox to prompt the user to clean up the mailbox, and when it is determined that the available capacity of the user mailbox is not less than the number of bytes contained in the returned mail, the cached Emails are sent to the user's mailbox.

Embodiments of the present invention provide a mail sending method, system and device for mailbox overflow. In the method, when the mailbox overflows and the user mail is returned, the returned mail is cached, and the mobile terminal corresponding to the user mailbox is instructed to prompt the user to send the mail. A cleaning operation, when the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, resend the cached mail to the user's mailbox. Since the bounced mail is cached in the embodiment of the present invention, and the user is prompted to clean up the user's mailbox, as long as the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, the cached mail will be sent to the user's mailbox , thereby avoiding the omission of information received by users.

Description of drawings

Fig. 1 is the mail sending process for mailbox overflow provided by the embodiment of the present invention;

Fig. 2 is the detailed implementation of the mail sending method for mailbox overflow provided by the embodiment of the present invention;

3 is a schematic structural diagram of a mail sending device for mailbox overflow provided by an embodiment of the present invention;

Fig. 4 provides for the implementation of the present invention in combination with the device shown in Fig. 3, the process of sending mail when the mailbox overflows;

Fig. 5 is yet another mail sending process for mailbox overflow provided by the embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an email sending system with mailbox overflow provided by the implementation of the present invention.

Detailed ways

In order to effectively improve the accuracy of the information received by the user, the embodiment of the present invention provides a mail sending method for mailbox overflow. In this method, when the mailbox overflows and returns the user mail, the returned mail is cached. Resend the cached mail to the user mailbox when the available capacity of is not less than the number of bytes contained in the bounced mail. Since the bounced mail is cached in the embodiment of the present invention, and the user is prompted to clean up the user's mailbox, as long as the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, the cached mail will be sent to the user's mailbox , thereby avoiding the omission of information received by users.

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Because the user registers for the user mailbox in the mail server when applying for the user mailbox. After receiving the user's registration information, the mail server allocates a certain amount of storage space for the registered user, and the storage space is the storage space for the user's mailbox. The storage space of the user's mailbox can be located inside the mail server, or in other devices that can be controlled by the mail server.

Fig. 1 provides for the mail sending process of mailbox overflow that the embodiment of the present invention provides, and this process comprises the following steps:

S101: Caching emails returned by user mailboxes.

When the user's mailbox is full, when the user's mailbox receives mail again, the user's mailbox will overflow, that is, the mail cannot be received, and the mail will be returned.

When the email sent by the user's mailbox is rolled back due to overflow, in the embodiment of the present invention, in order to avoid the problem of missing information received by the user, the rolled back email can be cached.

In this embodiment of the present invention, the device for caching the rollback mail may be a mail sending device for mailbox overflow, and the device may be located in the mail server, or may be located in the queuing engine in the mail server. When the user's mailbox is stored inside the mail server, the mail server can directly cache the bounced mail, for example, in a caching module. When the user's mailbox is not located inside the mail server, the queuing engine can cache the bounced mail in the local cache module or in its own cache space.

S102: Instruct the mobile terminal corresponding to the user's mailbox to perform an operation of prompting the user to clean up the mailbox.

In the embodiment of the present invention, the user mailbox of the overflow mail is the user's mobile phone mailbox, so according to the information of the user's mobile phone mailbox, the Subscriber Identity Module (Subscriber Identity Module, SIM) card of the mobile terminal corresponding to the mobile phone mailbox can be known The identification information is the card number information of the SIM card of the mobile terminal.

Or, when each user registers the user mailbox, the SIM card identification information of the user's mobile terminal can be obtained, and the corresponding relationship between the user mailbox and the user's mobile terminal SIM card identification information can be stored locally. When the mail is returned, the SIM card identification information of the mobile terminal corresponding to the user mailbox can be determined according to the information of the user mailbox of the returned mail.

S103: Determine that the available capacity of the user mailbox is not less than the number of bytes contained in the returned email, and send the cached email to the user mailbox.

In the embodiment of the present invention, in order to effectively improve the accuracy of the user's information acquisition, the mail sending device (hereinafter referred to as the device) for overflowing the mailbox can permanently save the mail returned by the user's mailbox. When it is determined that there is enough space in the user's mailbox, That is, when the available capacity of the user's mailbox is not less than the number of bytes contained in the returned email, the stored email is sent to the user's mailbox. Or in order to save the cache space of the device, in the embodiment of the present invention, the time for the device to cache the mails returned by the user's mailbox can be a time length T set according to needs. When within this time length, it is judged whether the available capacity of the user's mailbox is Not less than the number of bytes contained in the returned mail, when it is judged that the available capacity of the user mailbox is not less than the number of bytes contained in the returned mail, the cached mail is sent to the user mailbox.

When the length of time T for caching the mail returned by the user mailbox, there is no enough space in the user mailbox, that is, when the available capacity of the user mailbox is less than the number of bytes contained in the returned mail, the timeliness of the mail is considered to be poor , in order to save cache space, cache other bounced emails with strong timeliness, and discard the cached emails.

Since the cache space for caching bounced emails also has a certain capacity, when the flow of bounced emails is large within a certain period of time, when the device receives bounced emails and determines that there is no available capacity in the cache space, the cache When the remaining capacity of the space is less than the number of bytes contained in the returned email, the device will identify the sender's information of the returned email, specifically to identify the sender's user mailbox information, and send the returned email to the sender email address of the user in order to notify the sender.

Fig. 2 is the detailed implementation of the mail sending method for mailbox overflow provided by the embodiment of the present invention, the method includes:

S201: The device caches the bounced emails from the user's mailbox, and determines the time length for caching the bounced emails as T.

S202: Instruct the mobile terminal corresponding to the user's mailbox to perform an operation of prompting the user to clean up the mailbox.

S203: Judging whether the time length for caching the returned mail is not greater than T, if the judging result is yes, go to step S204, otherwise, go to step S206.

S204: Judging that the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, if the judging result is yes, go to step S205; otherwise, go to step S203.

S205: Send the cached email to the user mailbox.

S206: When it is determined that there is not enough space in the user mailbox, discard the cached email.

The above step S203 may also be performed before step S202, and is not limited to the implementation solution of the above embodiment.

FIG. 3 is a schematic structural diagram of a mail sending device for mailbox overflow provided by an embodiment of the present invention. The mail server includes: a cache module 31 and a control module 32 .

Caching module 31, used for caching the mail returned by user's mailbox;

The control module 32 is used to instruct the mobile terminal corresponding to the user mailbox to prompt the user to clean up the mailbox, and when it is determined that the available capacity of the user mailbox is not less than the number of bytes contained in the returned mail, the cached The above email is sent to the user mailbox.

In the embodiment of the present invention, the control module 32 may be a queuing engine, and the queuing engine is located in the mail server, and the cache module may be a storage space.

In the embodiment of the present invention, the control module 32 determines the available capacity of the user's mailbox. It may be that the control module 32 actively detects the available capacity of the user's mailbox, or the user's mailbox determines its own capacity according to the available capacity information reported by the user after cleaning. The available capacity is reported to the control module 32, and the control module 32 determines the available capacity of the user's mailbox according to the available capacity reported by the user's mailbox.

Specifically, the control module 32 is specifically configured to monitor the user's cleaning operation on the user mailbox, and determine the available capacity of the user mailbox after cleaning by the user.

Alternatively, the control module 32 is specifically configured to determine the available capacity of the user's mailbox after receiving the available capacity information reported by the user's mailbox after cleaning.

In addition, when the caching module 31 caches the email returned by the user mailbox for a certain length of time, the control module 32 is further configured to, according to the length of time for caching the email, within this time length, determine whether the user mailbox is available. Whether the capacity is not less than the number of bytes contained in the returned mail, and when it is determined that the available capacity of the user mailbox is not less than the number of bytes contained in the returned mail, send the cached mail to the user mailbox . The control module 32 is further configured to discard the cached mail when it is determined that the available capacity of the user mailbox is less than the number of bytes contained in the returned mail within the time period.

The control module 32 is also used to identify the user mailbox of the sender of the returned mail when it is determined that the remaining capacity of the cache space in the cache module 31 for buffering the returned mail is less than the number of bytes contained in the returned mail information, and send the bounced email to the user mailbox.

Fig. 4 provides for the implementation of the present invention in combination with the device shown in Fig. 3, the process of sending mail when the mailbox overflows, and in this process, the control module is used as an example to describe the queuing engine, and the process includes the following steps:

S401: When the user's mailbox is full, after receiving the user's mail, return the user's mail.

S402: The queuing engine receives the user email returned by the user mailbox.

S403: The queuing engine parses the returned user email, obtains information of the user mailbox, and saves an index of the user mailbox for the user mailbox.

S404: The queuing engine sends the returned user email to a corresponding location of the caching module for caching according to the index of the locally stored user mailbox.

S405: The queuing engine sends information prompting the user to clean up the mailbox to the mobile terminal corresponding to the mailbox of the user.

S406: The queuing engine listens to the cleaning operation of the user's mailbox by the user, and determines the available capacity of the user's mailbox after cleaning by the user.

S407: When it is judged that the available capacity is not less than the number of bytes contained in the returned email, determine that there is sufficient space in the user mailbox.

S408: The queuing engine sends a request to the caching module to acquire the user emails cached in the corresponding location according to the information of the user mailboxes judged to have sufficient space and the index of the locally stored user mailboxes.

S409: The caching module sends the user mail cached at the corresponding location to the queuing engine according to the request sent by the queuing engine.

S410: The queuing engine sends the received user email to a corresponding user mailbox.

After the queuing engine receives the mail returned by the user's mailbox, in order to judge whether the cached mail is sent, it needs to analyze the returned mail to obtain the information of the user's mailbox in the mail, that is, the information of the specific recipient's mailbox. After the queuing engine obtains the information of the user mailbox, it saves the index of the user mailbox for the user mailbox, and notifies the cache module to save the information of the user mailbox to the corresponding location, that is, the cache module corresponding to the local index corresponding position. When the queuing index determines that there is enough space in the user's mailbox, that is, when it is judged whether the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, according to the index of the user's mailbox stored locally, send to the cache module to obtain the returned A mail request, wherein the request carries information about the location of the mail cache. After receiving the request, the caching module provides the mails cached at the corresponding location to the queuing index according to the location information carried in the request, so as to realize resending of the cached mails.

In order to facilitate the queuing engine to determine whether there is enough space in the user mailbox according to the information of the number of bytes contained in the mail returned by the user mailbox, the queuing engine can obtain the information of the number of bytes contained in the mail when parsing the mail, and Store information about the number of bytes contained in the message locally against the index of the user's mailbox.

Since the queuing engine can analyze each email, obtain and save the information of the number of bytes contained in each email, when multiple emails returned by a certain user mailbox are cached in the cache module, in order to facilitate the queuing engine for the returned emails To determine whether there is enough space in the user mailbox, the queuing engine can also store the time information of receiving each bounced email for each bounced email received. The queuing engine can determine whether there is enough space in the user mailbox according to the time sequence of the received bounced emails and whether the number of bytes contained in the email with the earliest bounce time in the cached bounced emails is not greater than the available capacity of the user mailbox.

For example, when the queuing engine receives each email returned by a certain user's mailbox, it parses each email, obtains and saves the information of the number of bytes contained in each email, and saves the time information of each returned email received . Specifically, for example, the saved times of receiving bounced emails from a certain user mailbox are 8:29, 8:31, and 9:12 respectively, and the bytes contained in each bounced email are 32.5K, 67K, and 24K, respectively. Then when determining whether there is enough space in the user mailbox, the queuing engine uses the 32.5K bytes contained in the received mail with a return time of 8:29 and the available capacity of the user mailbox to determine whether there is enough space in the user mailbox. Or the queuing engine can also determine whether there is enough space in the user's mailbox according to the byte number information contained in all the bounced mails of a certain user's mailbox in the cache. The specific implementation method is the same as above, and will not be repeated here.

The queuing engine can listen to the cleaning operation of the user's mailbox based on the Messaging Application Programming Interface (MAPI). The above embodiment is explained by the queuing engine automatically listening to the cleaning operation of the user's mailbox to determine whether there is enough space in the user's mailbox. The user mailbox reports its own available capacity information to the queuing engine according to the user's cleaning, and the process of determining whether there is enough space in the user mailbox through the queuing engine is similar to the above process, and will not be repeated here.

In the embodiment of the present invention, when the mail server caches the mails returned by the user's mailbox locally, and then sends a message prompting the user to clean up the mailbox to the mobile terminal corresponding to the user's mailbox, the mail server notifies the SMS gateway to send the message to the user through the push gateway. The mobile terminal corresponding to the mailbox. Specifically, the mail server sends information to the push gateway to send prompt information to the mobile terminal corresponding to the user mailbox, and the information includes the SIM card identification information of the mobile terminal corresponding to the user mailbox.

After the push gateway receives the information, it sends the information to the short message gateway, and the information sent by the push gateway includes the SIM card identification information of the mobile terminal corresponding to the user mailbox. The SMS gateway receives the information sent by the push gateway, generates information prompting the user to clean up the mailbox according to the information stored locally, and sends the message prompting the user to clean up the email to the mobile terminal corresponding to the user mailbox according to the SIM card identification information of the mobile terminal .

The SMS gateway locally saves the information prompting the user to clean up the mail. Therefore, when the SMS gateway receives the information sent by the push gateway to send the reminder information to the mobile terminal corresponding to the user mailbox, it generates a message prompting the user to clean up the email according to the locally saved information. The cleared information is sent to the mobile terminal.

The message reminding the user to clean up the mail stored locally by the SMS gateway can be a general short message, and when the mobile terminal receives the short message, it will provide the short message to the user. Or in the embodiment of the present invention, in order to improve the user's cleaning efficiency to the user's mailbox, the short message gateway sends trade information to the mobile terminal, so after the bottom module of the mobile terminal receives the information, it automatically pushes the login information of the user's mailbox to the user, And according to the information saved by itself, provide the user with the information of cleaning up the mailbox. Specifically, for example, after the mobile terminal receives the trade information sent by the SMS gateway, the mobile phone mailbox client is automatically triggered, and the mobile phone mailbox client pops up a message about cleaning up the mailbox of the user.

Fig. 5 is another mail sending process for mailbox overflow provided by the embodiment of the present invention, in the process, the mail sending for mailbox overflow is located in the mail server as an example for illustration, and the process includes the following steps:

S501: The mail server locally caches the returned mail from its own user mailbox, and determines that the time length for caching the returned mail is T.

S502: The mail server sends to the push server information about sending prompt information to the mobile terminal corresponding to the user mailbox.

S503: According to the received information, the push server sends to the short message gateway information for sending prompt information to the mobile terminal corresponding to the user mailbox.

S504: The short message gateway generates information prompting the user to clean up the mailbox according to the received information and the information stored locally, and sends the generated information to the mobile terminal corresponding to the user mailbox.

S505: The mobile terminal parses the received information prompting the user to clean up the mailbox.

S506: The mobile terminal provides the user with login information of the user's mailbox, and provides the user with information about cleaning up the mailbox according to the information stored by itself.

S507: The mail server judges whether the time length for caching the bounced mail is not greater than T, and if the judgment result is yes, go to step S508; otherwise, go to step S510.

S508: Judging whether the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, if the judging result is yes, go to step S509; otherwise, go to step S507.

S509: Send the cached email to the user mailbox.

S510: When it is determined that there is not enough space in the user mailbox, discard the cached email.

In the above steps, S507 can be executed before or after any step between step S502 and step S506, and is not limited to the above embodiment of the present invention. The execution of step S507 is specifically determined according to the listening time interval saved by the mail server.

Fig. 6 is a schematic structural diagram of a mail sending system with mailbox overflow provided by the implementation of the present invention, the system includes:

The mail server 61 is used to cache mails returned by the user mailbox, instruct the mobile terminal corresponding to the user mailbox to prompt the user to clean up the mailbox, and determine that the available capacity of the user mailbox is not less than the bytes contained in the returned mail number of times, send the cached mail to the user mailbox;

The mobile terminal 62 is configured to receive information prompting the user to clean up emails, and prompt the user for the information.

The system also includes:

Push gateway 63, configured to receive the information sent by the mail server to send prompt information to the mobile terminal corresponding to the user mailbox;

The short message gateway 64 is configured to receive the information sent by the push gateway, and send information prompting the user to clean up the mailbox to the mobile terminal corresponding to the user mailbox according to the locally stored information.

Embodiments of the present invention provide a mail sending method, system and device for mailbox overflow. In the method, when the mailbox overflows and the user mail is returned, the returned mail is cached, and the mobile terminal corresponding to the user mailbox is instructed to prompt the user to send the mail. A cleaning operation, when the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, resend the cached mail to the user's mailbox. Since the bounced mail is cached in the embodiment of the present invention, and the user is prompted to clean up the user's mailbox, as long as the available capacity of the user's mailbox is not less than the number of bytes contained in the returned mail, the cached mail will be sent to the user's mailbox , thereby avoiding the omission of information received by users.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (11)

1., for the e-mail sending method that mailbox overflows, it is characterized in that, comprising:

When subscriber mailbox because overflow the mail of rollback transmission, the mail that cache user mailbox is return, wherein, when subscriber mailbox is occupied full, described subscriber mailbox will overflow; And

The mobile terminal that described subscriber mailbox is corresponding is indicated to carry out pointing out user to carry out the operation of mailbox cleaning;

When determining that the active volume of described subscriber mailbox is not less than the byte number that the described mail package of returning contains, by the described mail sending of buffer memory to described subscriber mailbox, wherein, determine that the active volume of described subscriber mailbox comprises:

Listen for user to the cleaning operation of described subscriber mailbox, determine user clear up after the active volume of described subscriber mailbox; Or

Receive described subscriber mailbox according to the active volume information reported after user's cleaning, determine the active volume of described subscriber mailbox.

2. the method for claim 1, is characterized in that, the operation indicating mobile terminal corresponding to described subscriber mailbox to carry out pointing out user to carry out mailbox cleaning comprises:

By pushing gateway notifying messages gateway, the information of the prompting user preserved in this Short Message Service Gateway being carried out mail cleaning is sent to mobile terminal corresponding to described subscriber mailbox, indicates described mobile terminal to provide described information to user.

3. the method as described in as arbitrary in claim 1 to 2, is characterized in that, when determining the byte number that the active volume of described subscriber mailbox contains as many as the described mail package of returning, is comprised by the described mail sending of buffer memory to described subscriber mailbox:

The time span of mail according to buffer memory, in this time span, judges the byte number whether active volume of described subscriber mailbox is not less than the described mail package of returning and contains;

When determining that the active volume of described subscriber mailbox is not less than the byte number that the described mail package of returning contains, by the described mail sending of buffer memory to described subscriber mailbox.

4. method as claimed in claim 3, it is characterized in that, described method also comprises:

When in described time span, when determining that the active volume of described subscriber mailbox is less than the byte number that the described mail package of returning contains, the described mail of buffer memory is abandoned.

5. the method for claim 1, is characterized in that, described method also comprises:

When determining that residual capacity that buffer memory returns the spatial cache of mail is less than the byte number that this mail package of returning contains, identify the subscriber mailbox information of the sender of the described mail return, by the described mail sending return to this subscriber mailbox.

6., for the mail transmission system that mailbox overflows, it is characterized in that, described system comprises:

Mail server, for the mail sent because of spilling rollback when subscriber mailbox, the mail that cache user mailbox is return, wherein, when subscriber mailbox is occupied full, described subscriber mailbox will overflow, the mobile terminal that described subscriber mailbox is corresponding is indicated to carry out pointing out user to carry out the operation of mailbox cleaning, when determining that the active volume of described subscriber mailbox is not less than the byte number that the described mail package of returning contains, by the described mail sending of buffer memory to described subscriber mailbox, wherein, determine that the active volume of described subscriber mailbox comprises:

Listen for user to the cleaning operation of described subscriber mailbox, determine user clear up after the active volume of described subscriber mailbox; Or

Receive described subscriber mailbox according to the active volume information reported after user's cleaning, determine the active volume of described subscriber mailbox;

Mobile terminal, carries out the information of mail cleaning, and points out described information to user for receiving prompting user.

7. system as claimed in claim 6, it is characterized in that, described system also comprises:

Push gateway, the mobile terminal corresponding to described subscriber mailbox sent for receiving described mail server sends the information of information;

Short Message Service Gateway, for receiving the information that described propelling movement gateway sends, according to the information that this locality is preserved, sends to the mobile terminal that described subscriber mailbox is corresponding the information that prompting user carries out mailbox cleaning.

8., for the mail sending device that mail overflows, it is characterized in that, described device comprises:

Cache module, for the mail sent because of spilling rollback when subscriber mailbox, the mail that cache user mailbox is return, wherein, when subscriber mailbox is occupied full, described subscriber mailbox will overflow;

Control module, be used to indicate mobile terminal corresponding to described subscriber mailbox to carry out pointing out user to carry out the operation of mailbox cleaning, listen for user is to the cleaning operation of described subscriber mailbox, determine user clear up after the active volume of described subscriber mailbox, or receive described subscriber mailbox according to the active volume information reported after user's cleaning, determine the active volume of described subscriber mailbox, when determining that the active volume of described subscriber mailbox is not less than the byte number that the described mail package of returning contains, by the described mail sending of buffer memory to described subscriber mailbox.

9. device as claimed in claim 8, it is characterized in that, described control module specifically for, the time span of mail according to buffer memory, in this time span, judge the byte number whether active volume of described subscriber mailbox is not less than the described mail package of returning and contains, when determining that the active volume of described subscriber mailbox is not less than the byte number that the described mail package of returning contains, by the described mail sending of buffer memory to described subscriber mailbox.

10. device as claimed in claim 9, is characterized in that, described control module also for, when in described time span, when determining that the active volume of described subscriber mailbox is less than the byte number that the described mail package of returning contains, the described mail of buffer memory is abandoned.

11. devices as claimed in claim 8, it is characterized in that, described control module also for, when determining that residual capacity that buffer memory returns the spatial cache of mail is less than the byte number that this mail package of returning contains, identify the subscriber mailbox information of the sender of described mail return, by the described mail sending return to this subscriber mailbox.