F=q
250 versus 252 return for SMTP VRFY V8.8 and later
Prior to RFC1123, a successful reply to the SMTP VRFY command was always prefixed with a 250, meaning that sending to this address was likely to result in successful delivery:
VRFY user
250 user@here.us.edu (Full Name)
Here, sendmail states (with the
250
) that it
interpreted the address as valid
locally and that delivery or relaying
to another site would be attempted.
RFC1123 now requires that shades of meaning be conveyed in that success code, so the correct prefix should be 252, which means that the host will accept the address and might attempt to relay it elsewhere.
If the F=q
delivery
agent flag is set, sendmail
returns the 250 prefix; otherwise, it returns the
252 prefix. It should be set only for delivery
agents doing local delivery. For configuration files
earlier than version 7, the F=q
delivery agent flag is
automatically set for the local
, prog
, and *file*
delivery agents.
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