[Mimedefang] helo callback

Dale Moore Dale.Moore at cs.cmu.edu
Fri Nov 7 13:06:29 EST 2014

Perhaps someone can explain this behavior..
Below is what happens in chronological order.

Client: connect to server (sendmail 8.14.9)
Mimedefang filter_relay: return('CONTINUE');
Server: 220 somehost.cs.cmu.edu ESMTP Sendmail 8.14.9/8.14.9; Fri, 7 Nov 2014 12:56

Client: Helo naughtywords
Mimedefang filter_helo: return('REJECT', 'I do not like naughtywords');
Server: 220 somehost.cs.cmu.edu Hello someclient.cs.cmu.edu [128.2.x.x], pleased to meet you

Client: Mail From:<SomeValidAddress at cs.cmu.edu>
Mimedefang filter_sender: return('CONTINUE');
Server: 554 5.7.1 I do not like naughtywords

Note how the mimedefang filter_helo does not affect the SMTP response immediately,
but is instead delayed until after the sender has been specified.
I would have instead expected it to happen immediately.

Details: Sendmail 8.14.9 Solaris 10 (and linux has same behaivor)
Sendmail is not configured with delay_checks.
Mimedefang version 2.75 .

Explanations appreciated.
Dale Moore

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