Submission and CHUNKING

[Stephan Bosch]

Op 25/10/2018 om 09:53 schreef Paul Hecker:
> Hi,
>
> It seems that there is an issue with the submission service when the SMTP server advertises chunking (I use Exim v4.91). I tried this with Dovecot v2.3.3 and current master and could reproduce it with both versions.
>
> My setup is that dovecot submission proxies to Exim on port 10025. The first mail gets through without any issues, but the second email will not get send. I had this issue at first with Apple Mail (it just sends a QUIT and shows an error) and could reproduce it with the OpenDMARC report perl script.
>
> You can find a little Perl script attached to reproduce it. It seems to me that Dovecot sends an (unexpected or mixed up) second answer to the client. If I add a “$smtp->getline();” (line 110) sending multiple emails works again.
>
> Another workaround is to disable CHUNKING in Exim (in this case only on the “proxy port”):
>
> chunking_advertise_hosts = ${if eq{$received_port}{10025}{}{*}}

Thanks for this detailed bug report. I can reproduce it here. Working on 
a fix. FYI, it is more general than just CHUNKING: it relates to 
relaying multi-line replies.

Regards,

Stephan.