submission configuration issues

[Stephan Bosch]

On 23/07/2019 17:13, Jean-Daniel Dupas via dovecot wrote:
> Hello,
>
> I'm having trouble configuring the submission proxy.
>
> I have configured the submission service as follow:
>
> submission_host = smtp.example.com
> submission_relay_host = localhost
> submission_relay_port = 8587
> submission_relay_rawlog_dir = /var/log/dovecot/
> submission_relay_trusted = yes
>
> My main issue is that until I login, dovecot-submission won't connect to the backend and query the capabilities and so won't report the right capabilities.
>
> That mean that the first EHLO message don't get the right capabilities list.
>
> "
> EHLO example.com
>
> 250-smtp.example.com
> 250-8BITMIME
> 250-AUTH PLAIN LOGIN
> 250-BURL imap
> 250-CHUNKING
> 250-ENHANCEDSTATUSCODES
> 250-SIZE
> 250 PIPELINING
> "
>
> This list don't contains VRFY, DNS, and SIZE is not specified (all of these is present in backend EHLO response).
> After login, if I send an new EHLO command, everything is properly reported. The raw log shows that unlike what the documentation says,
> dovecot don't try to connect to the backend until the user is properly logged.
>
> In my raw log I show that after I logged in dovecot-submission, the later open a connection to the backend and send a X-CLIENT command.
>
>
> Now, if I try to force the capabilities by using:
>
> submission_backend_capabilities = VRFY 8BITMIME DSN
>
> dovecot properly reports all SMTP capabilities in the first EHLO response, but it completely stops emitting X-CLIENT command to the backend
> and try to simply forward the command without authentication, which result in postfix rejecting the command with an unauthorized user error.
>
> What is wrong with my configuration ?
> Thanks.

Can you send us your complete configuration (output from `dovecot -n`)?

Regards,

Stephan.