diff --git a/Doc/library/email.policy.rst b/Doc/library/email.policy.rst
index f4777bb2462138..5842d05baf38ef 100644
--- a/Doc/library/email.policy.rst
+++ b/Doc/library/email.policy.rst
@@ -454,9 +454,10 @@ added matters.  To illustrate::
 
 
       The name is parsed as everything up to the '``:``' and returned
-      unmodified.  The value is determined by stripping leading whitespace off
-      the remainder of the first line, joining all subsequent lines together,
-      and stripping any trailing carriage return or linefeed characters.
+      stripped of trailing whitespace.  The value is determined by stripping
+      leading whitespace off the remainder of the first line, joining all
+      subsequent lines together, and stripping any trailing carriage
+      return or linefeed characters.
 
 
    .. method:: header_store_parse(name, value)
diff --git a/Lib/email/_policybase.py b/Lib/email/_policybase.py
index c9cbadd2a80c48..a7c1310fefee22 100644
--- a/Lib/email/_policybase.py
+++ b/Lib/email/_policybase.py
@@ -292,15 +292,15 @@ def _sanitize_header(self, name, value):
 
     def header_source_parse(self, sourcelines):
         """+
-        The name is parsed as everything up to the ':' and returned unmodified.
-        The value is determined by stripping leading whitespace off the
-        remainder of the first line, joining all subsequent lines together, and
-        stripping any trailing carriage return or linefeed characters.
+        The name is parsed as everything up to the ':' and returned stripped
+        of any trailing whitespace. The value is determined by stripping leading
+        whitespace off the remainder of the first line, joining all subsequent
+        lines together, and stripping any trailing carriage return or linefeed characters.
 
         """
         name, value = sourcelines[0].split(':', 1)
         value = value.lstrip(' \t') + ''.join(sourcelines[1:])
-        return (name, value.rstrip('\r\n'))
+        return (name.rstrip(' \t'), value.rstrip('\r\n'))
 
     def header_store_parse(self, name, value):
         """+
diff --git a/Lib/email/feedparser.py b/Lib/email/feedparser.py
index 06d6b4a3afcd07..46790b3cd63cbb 100644
--- a/Lib/email/feedparser.py
+++ b/Lib/email/feedparser.py
@@ -34,7 +34,7 @@
 NLCRE_crack = re.compile(r'(\r\n|\r|\n)')
 # RFC 2822 $3.6.8 Optional fields.  ftext is %d33-57 / %d59-126, Any character
 # except controls, SP, and ":".
-headerRE = re.compile(r'^(From |[\041-\071\073-\176]*:|[\t ])')
+headerRE = re.compile(r'^(From |[\041-\071\073-\176]*[ \t]*:|[\t ])')
 EMPTYSTRING = ''
 NL = '\n'
 boundaryendRE = re.compile(
diff --git a/Lib/test/test_email/data/msg_48.txt b/Lib/test/test_email/data/msg_48.txt
new file mode 100644
index 00000000000000..999b32b08c8c6a
--- /dev/null
+++ b/Lib/test/test_email/data/msg_48.txt
@@ -0,0 +1,7 @@
+Subject: Regarding messages containing whitespace that follow field names
+To: receiver@example.org
+x-whitespace-after-fieldname       : value
+Date: Fri, 20 May 2022 18:13:19 +1200
+From: sender@example.org
+
+Field names can be followed by arbitrary whitespace
diff --git a/Lib/test/test_email/test_email.py b/Lib/test/test_email/test_email.py
index 39d4ace8d4a1d8..e08149490fb6fd 100644
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -431,6 +431,14 @@ def test_get_param_funky_continuation_lines(self):
         msg = self._msgobj('msg_22.txt')
         self.assertEqual(msg.get_payload(1).get_param('name'), 'wibble.JPG')
 
+    def test_whitespace_after_fieldname(self):
+        # As part of obsolete email syntax, fieldnames can be followed by arbitrary whitespace
+        msg = self._msgobj("msg_48.txt")
+
+        self.assertEqual(msg["x-whitespace-after-fieldname"], "value")
+        self.assertEqual(msg.get_payload(),
+                         "Field names can be followed by arbitrary whitespace\n")
+
     # test_headerregistry.TestContentTypeHeader.semis_inside_quotes
     def test_get_param_with_semis_in_quotes(self):
         msg = email.message_from_string(
diff --git a/Misc/NEWS.d/next/Library/2022-05-24-15-55-09.gh-issue-93158.KH0YPY.rst b/Misc/NEWS.d/next/Library/2022-05-24-15-55-09.gh-issue-93158.KH0YPY.rst
new file mode 100644
index 00000000000000..7cbfbd7443a46e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-05-24-15-55-09.gh-issue-93158.KH0YPY.rst
@@ -0,0 +1,2 @@
+The :mod:`email` library now parses messages that use obsolete email syntax where
+header field names can be followed by whitespace.