1 Topic by heavygale

  • heavygale
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Topic: No DKIM signature for Mails sent via SMPT

I started using iRedMail with Version 0.9.2 and did upgrade it to 0.9.3. It's running on debian 8.2 with MySQL and Nginx. Accounts are managed using Postfix Admin 2.93. Configured transport in the database table mail.domain is "dovecot".
- postconf -n
- /etc/amavis/conf.d/50-user

I noticed that since the update to 0.9.3. only mails sent via roundcube do get signed with DKIM but mails sent with the application on my local computer via SMTP don't get DKIM-signed.

/var/log/mail.info when sending an mail to an external domain:
- using roundcube webmail
- using mail client on my computer

Maybe I did a mistake when upgrading the Amavisd config, but I can't find the error.

Thanks for your help in advance!

Greetings from germany.

----

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2 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: No DKIM signature for Mails sent via SMPT

*) Your have correct settings of Amavisd changes in iRedMail-0.9.3 release. We still need your /etc/postfix/master.cf (just 'submission') to verify it.

*) How did you send email with mail client on your computer? Does it use port 587? Email sent through port 587 should have DKIM signature.

*) If you submit email locally, Postfix will pick it up and use transport 'pickup' (defined in /etc/postfix/master.cf), it doesn't go through any content filter (in our case, it's Amavisd). To overcome this, you can update /etc/postfix/master.cf to use content filter like this:

pickup ...
    -o content_filter=smtp-amavis:[127.0.0.1]:10026

Note: it's port 10026, not 10024.

3 Reply by heavygale

  • heavygale
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Re: No DKIM signature for Mails sent via SMPT

/etc/postfix/master.cf
This should be fine too, as I only added the one line as shown in the upgrade instructions.

My mail client was configured to use port 25 (I have no idea why), I changed it to port 587 and now the email got a DKIM signature. -> Good guess, that was easy to fix, thanks for your help!

Only roundcube seems to submid email locally - dkim signing works in this case (therefore i keep 'pickup' as is).

Thank you and enjoy your cub of coffee. wink

4 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: No DKIM signature for Mails sent via SMPT

*) Port 25 is not used for submitting email in iRedMail-0.9.3, it's used for postscreen service.
*) Although Roundcube is running on localhost, but all sent emails go through port 587, so they will have DKIM signature.
*) Email sent from localhost without smtp authentication and port 587 will be processed by transport 'pickup' (defined in /etc/postfix/master.cf), it doesn't use content filter on port 10026, so it's not same as Roundcube, and not DKIM signature.

Hope it helps.

And thanks very much for buying me a cup of coffee.

5 Reply by richard.oflynn (edited by richard.oflynn 2016-08-17 01:11:40)

  • richard.oflynn
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  • Registered: 2016-08-17
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Re: No DKIM signature for Mails sent via SMPT

IGNORE THIS REPLY. FIREWALL WAS PROBLEM IN THE END!

This information is very helpful thank you.

What does one have to configure / what are settings to get emails sent from a client such as outlook, mac to get the DKIM signature?

Actually, just read a little more, I see someone configured to use port 587, but my client wont connect when I set this?

Any suggestions where to look for fault?

Thanks

RIchard.

ZhangHuangbin wrote:

*) Port 25 is not used for submitting email in iRedMail-0.9.3, it's used for postscreen service.
*) Although Roundcube is running on localhost, but all sent emails go through port 587, so they will have DKIM signature.
*) Email sent from localhost without smtp authentication and port 587 will be processed by transport 'pickup' (defined in /etc/postfix/master.cf), it doesn't use content filter on port 10026, so it's not same as Roundcube, and not DKIM signature.

Hope it helps.

And thanks very much for buying me a cup of coffee.