Wietse Venema:
> Erwin Authried:
> > I'm routing messages to a couple of servers with the transport map
> > mechanism. I'm using recipient address verification to avoid bounce
> > messages. This works fine with mail servers that send a 550 response,
> > for example:
> >
> > RCPT TO: non-existent-u...@somedomain.com
> > 550 5.7.1 Unable to deliver to non-existent-u...@somedomain.com
> >
> > There are some mail servers with qmail that do not send an error
> > response after RCPT TO:, but later after the "DATA" command:
> >
> > RCPT TO: non-existent-u...@somedomain.com
> > 250 OK
> > DATA
> > 554 sorry, invalid mailbox name(s). (#5.1.1)
Is this the reply to DATA or end-of-data? If it is DATA, then
address verification is possible but it requires source code
changes to Postfix:
- After successful RCPT TO, do not assume that the recipient exists,
but send DATA and disconnect after the DATA response is received.
This will cause extra noise in the logfile, therefore it should be
configurable:
- Configure what sites reject recipients after DATA. The list of
such domains is limited, so this is not a big burden.
Wietse
