Incoming emails no longer processed, log showing Email can not be processed: Email::Receiver::EmptyEmailError

[MKorndoerfer (Martin Korndoerfer)]

Suddenly the system stopped processing emails. In the log, I can see the following entry:

Message (7560 copies reported)

Email can not be processed: Email::Receiver::EmptyEmailError



Backtrace

/var/www/discourse/lib/email/processor.rb:183:in `log_email_process_failure'
/var/www/discourse/lib/email/processor.rb:29:in `rescue in process!'
/var/www/discourse/lib/email/processor.rb:16:in `process!'
/var/www/discourse/lib/email/processor.rb:13:in `process!'
/var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:29:in `process_popmail'
/var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:49:in `block (2 levels) in poll_pop3'
/var/www/discourse/vendor/bundle/ruby/3.2.0/gems/net-pop-0.1.2/lib/net/pop.rb:669:in `each'
/var/www/discourse/vendor/bundle/ruby/3.2.0/gems/net-pop-0.1.2/lib/net/pop.rb:669:in `each_mail'
/var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:46:in `block in poll_pop3'
/var/www/discourse/vendor/bundle/ruby/3.2.0/gems/net-pop-0.1.2/lib/net/pop.rb:531:in `start'

I’ve checked the inbox and I can’t see any suspicious mail in there…

The error is not shown in the rejected list, as a matter of fact, nothing at all getting listed there anymore.

All the mails seems to remain in the inbox without being processed.

[thoka (Thomas Kalka)]

This happened to me once while polling mails via pop and getting into timeouts due to a huge inbox.

Do you delete received messages?

[MKorndoerfer (Martin Korndoerfer)]

I haven’t, but there aren’t that many mails. Around 30.

And I actually need them to be processed…

[thoka (Thomas Kalka)]

Did you try

Email::Processor does not expect to be called with mail=nil

I’ve made an update to prevent the error caused by is_bounce?. There is a site setting for tracking mail logs: SiteSetting.log_mail_processing_failures Log all email processing failures to /logs If this is enabled, the blank email error will still appear in the mail logs but won’t cause the job to fail like it does currently. I’ve added the commit details here for reference:

?

[MKorndoerfer (Martin Korndoerfer)]

Yes, this setting has been enabled all along.

[MKorndoerfer (Martin Korndoerfer)]

I think there’s sth wrong with the email provider. Strange things are happening…

Thanks for trying to help, if I’ll figure it out, I’ll let you know!

[thoka (Thomas Kalka)]

If I remember correct, I patched the code in the running discourse to ignore empty mails.

discourse/discourse/blob/2d074ad4a5f5370c135bc2c939f37c9453c296d6/lib/email/processor.rb#L16-L21

You could try to insert return if @mail.blank? before line 18.

Alternatively, you could try to remove the failing job from sidekiq.

(I would do a backup before such experiments)

[pfaffman (Jay Pfaffman)]

And if that fixes it, then this should be moved to bug.

[MKorndoerfer (Martin Korndoerfer)]

Just wait. It seems that the mail server is acting up. In addition to the empty mail error, I also get a read timeout, which I originally didn’t associate with the email process, but it is.

I’m currently talking with my mail hoster, who confirmed that there seems to be something wrong in his side.

As soon as I know more, I’ll let you know!

[MKorndoerfer (Martin Korndoerfer)]

Ok, we found the culprit. It was a single mail, as soon as I moved that mail into a separate folder, the rest of the mails were processed correctly.

An IMAP client can see that mail just fine. I’d send that mail’s raw contents (incl. headers and all) in a private message, if you want, so you can check and debug the reason for hanging the process.