I'm having some trouble with sender callout verification rejecting VERP
messages from various Google applications. I have an ACL that looks like
this
deny !verify = sender/callout
which is performing the callout check. However, it appears to be
downcasing the address before doing callout, which is causing unintended
failures. Here's an example with a real VERP address that has attempted
to deliver to us:
$ telnet 82.211.77.57 25
Trying 82.211.77.57...
Connected to uh.arachsys.com.
Escape character is '^]'.
220 uh.arachsys.com ESMTP Exim 4.68 Mon, 24 Sep 2007 16:25:44 +0100
HELO arachsys.demon.co.uk
250 uh.arachsys.com Hello arachsys.demon.co.uk [83.104.159.199]
MAIL FROM:<3p8n3RhAKBq8PRRdjcih-cdgTeanVddVaT.RdbRWgXhkjgQPcWdgXodc.Rdb@???>
250 OK
RCPT TO: <chris@???>
550-Verification failed for <3p8n3RhAKBq8PRRdjcih-cdgTeanVddVaT.RdbRWgXhkjgQPcWdgXodc.Rdb@???>
550-Called: 64.233.167.14
550-Sent: RCPT TO:<3p8n3rhakbq8prrdjcih-cdgteanvddvat.rdbrwgxhkjgqpcwdgxodc.rdb@???>
550-Response: 550 5.1.1 No such user x46si1487200pyg
550 Sender verify failed
421 uh.arachsys.com: SMTP command timeout - closing connection
Connection closed by foreign host.
Performing the verification steps manually myself:
$ telnet 64.233.167.14 25
Trying 64.233.167.14...
Connected to 64.233.167.14.
Escape character is '^]'.
220 mx.google.com ESMTP x46si1490466pyg
HELO arachsys.demon.co.uk
250 mx.google.com at your service
MAIL FROM:<>
250 2.1.0 OK
RCPT TO:<3p8n3RhAKBq8PRRdjcih-cdgTeanVddVaT.RdbRWgXhkjgQPcWdgXodc.Rdb@???>
250 2.1.5 OK
but if I downcase the recipient address in the same way it appears from
the 550 that Exim is:-
[...]
RCPT TO:<3p8n3rhakbq8prrdjcih-cdgteanvddvat.rdbrwgxhkjgqpcwdgxodc.rdb@???>
550 5.1.1 No such user x46si1490466pyg
I've tried both adding control=caseful_local_part to the ACL and (just in
case---although I can't see that it should have any effect!)
caseful_local_part to our remote SMTP router without success. Is there a
standard way to configure the callback not to downcase the address before
verification?
Cheers,
Chris.
