domainvrfy, localvrfy, novrfy) These keywords control PMDF's use of the VRFY command in its SMTP client. Under normal circumstances there is no reason for PMDF to issue a VRFY command as part of an SMTP dialogue --- the SMTP MAIL TO command should perform the same function that VRFY does and return an appropriate error. However, SMTP servers exist that will accept any address in a MAIL TO (and bounce it later), whereas they perform more extensive checking as part of a VRFY command.
Therefore PMDF can be configured to issue SMTP VRFY commands. The
keyword domainvrfy causes PMDF to issue a VRFY command
with a full address (e.g.,
user@host) as its argument. The
localvrfy keyword causes PMDF to issue a VRFY command with
just the local part of the address (e.g.,
user). novrfy is the default.