AssertEmail with strict mode does not check for DNS.

Symfony version(s) affected: 4.3

Description
When using

@Assert\Email(mode="strict")

There is no error for a fooBar@gmailcom email value

Possible Solution
The EmailValidator use

$strictValidator->isValid($email, new NoRFCWarningsValidation())

A better check could be

$strictValidator->isValid($email, new MultipleValidationWithAnd([new NoRFCWarningsValidation(), new DNSCheckValidation()]))

Provide feedback