On 09/20/2018 10:24 PM, Stephan Bosch wrote:
Op 20/09/2018 om 13:39 schreef Michael Goth:
On 09/20/2018 12:56 PM, Robert Schetterer wrote:
Am 20.09.2018 um 11:04 schrieb Michael Goth:
Hello,
I'm setting up Dovecot 2.3.2.1 as a submission proxy to a Postfix backend server. Dovecot announces CHUNKING, but the Postfix backend does not support (or announce) it.
HELO from Postfix:
220 backend.mydomain.com ESMTP Postfix (Ubuntu) ehlo test 250-backend.mydomain.com 250-PIPELINING 250-SIZE 104857600 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN
HELO from Dovecot proxy:
220 proxy.mydomain.com Dovecot ready. ehlo test 250-proxy.mydomain.com 250-8BITMIME 250-AUTH PLAIN LOGIN 250-BURL imap 250-CHUNKING 250-ENHANCEDSTATUSCODES 250-SIZE 250-STARTTLS 250 PIPELINING
When a client sends BDAT, Postfix closes the connection. Here's a log snippet from Postfix:
< MAIL FROM:<user@mydomain.com> > 250 2.1.0 Ok < RCPT TO:<some@recipient.com> > 250 2.1.5 Ok < BDAT 114098 LAST > 502 5.5.2 Error: command not recognized < Content-Type: multipart/alternative; boundary=Apple-Mail-55D35F74-2EB7-4B3B-A607-E421DD71C07A > 221 2.7.0 Error: I can break rules, too. Goodbye.
Apple Mail seems to ignore the fact that Postfix does not understand BDAT and Postfix does not like that :-)
From a quick glance at the code it seems CHUNKING is always added to the capabilities and that's not configurable. Is this a bug or am I doing something wrong?
Thanks,
Michael
that "may" version depend
http://www.postfix.org/features.html ... Postfix 3.4 SMTP server support for RFC 3030 CHUNKING (without BINARYMIME). ...
As far as I understand, Dovecot always adds certain capabilities. This is the responsible code (I think):
https://github.com/dovecot/core/blob/c8d03c3cab68328947a5afb47f48aef5b5a1e4a...
Dovecot adds the capability to the server side (facing the client), but not on the proxy client side (facing Postfix). If Postfix doesn't support CHUNKING, Dovecot will translate between BDAT from client and DATA towards Postfix. That's the way it is supposed to work anyway. I cannot reproduce your problem here with a quick test.
Can you enable mail_debug=yes (e.g. for that particular user) and show me the debug log of the proxy activity?
The output from
dovecot -nwould also be helpful.Regards,
Stephan.
I think I found the problem:
I am not using the submission_* config directives to configure the relay SMTP server. Instead, I'm using Dovecot's proxy feature for selecting a backend server based on the user's authentication. The submission_* directives are all unset.
When using the submission_* directives, Dovecot translates from BDAT to DATA. With my configuration, it seems to just relay all the commands to the backend server.
Now that I think about it, I'm not sure what dovecot can do in this case. It doesn't really know the supported capabilities until the user authenticates themself.
Regards, Michael