Zitat von Matthias Henze <lists(a)mhcsoftware.de>de>:
Some other interesting observations:
Even if I issue a VRFY to the Ciphermail Postfix it uses a SMTP chat
any way to verify the address. My firewall also does not use VRFY
and instead also uses a SMTP chat. As there is a special command to
verify addresses, why does no one make use of it?
The VRFY is from the time where MTA typically accept all destination
addresses and only later on find out if the recipient exists or not.
Today nearly every MTA first check if the recipient is allowed/valid
before accepting a mail so VRFY is useless and sometimes doesn even
work at all. Thats why the address verification is done with RCPT TO.
This is more of a Postfix question so you might have a look here