ESMTP Exim 4.89 - using Emacs VM for sending mail hangs

[Stas Burdan]

Hello all,

I have been using Emacs VM for sending mail via SMTP through hosting facility running cPanel and
ESMTP Exim for years, (it must have been 15 years now). This week I ran into an issue that some of my SMTP messages hang.
I narrowed the messages that hang down to a handful of conditions - which I suspect are related with encoding in the messages that I am replying to. When I reply to these messages, the process goes to the point of sending "." on the line by itself and just hangs there, as if the other side does not recognize that as a valid end of message.

When I compose a new message in Emacs and send it to the same recipients it works.
I don't control cPanel and can only provide the guidance to the hosting facility on what to do, and while they are working on the issue, I am not sure they have enough expertise to help.

I have been experiencing these issues for a week and it is seriously affecting my ability to send email, so I am stepping in to figure this out and help cPanel admin solve this.

versions of software:

GNU Emacs 23.3.1 (i686-pc-linux-gnu, GTK+ Version 2.24.10) of 2013-05-16 on komainu, modified by Debian

ESMTP Exim 4.89


Thank you in advance for your help!

 

[cPanelMichael]

Hello,

Could you check with your hosting provider and see if they notice any entries in /var/log/exim_mainlog when the issue is reproduced?

Thank you.

 

[Stas Burdan]

here is the log provided by the hosting facility. I changed to domain names in emails for privacy reasons. And only providing records with "data timeout (message abandoned)"

Please let me know if this gives you any further ideas.

Thank you



2017-07-26 19:27:00 1daYVs-0005po-FM => stas ([email protected], [email protected], [email protected]) <[email protected]> R=virtual_user T=dovecot_virtual_delivery C="250 2.0.0 <[email protected]> I+m1G3RPeVn1VwAAKB3gjA Saved"
2017-07-26 19:28:04 1daYWv-0005sc-BZ => stas ([email protected], [email protected], [email protected]) <[email protected]> R=virtual_user T=dovecot_virtual_delivery C="250 2.0.0 <[email protected]> EbTNDrRPeVn1VwAAKB3gjA Saved"
2017-07-26 19:31:38 SMTP connection identification H=c-76-19-64-7.hsd1.ma.comcast.net A=76.19.64.7 P=61587 U=altreco ID=593 [email protected] B=get_recent_authed_mail_ips_entry
2017-07-26 19:34:23 SMTP data timeout (message abandoned) on connection from c-76-19-64-7.hsd1.ma.comcast.net (captain) [76.19.64.7]:61587 F=<[email protected]>
2017-07-26 19:38:54 1daYhS-0006Ym-5l <= stas[email protected] H=(s534.c4.crucialp.com) [::1]:41484 P=esmtpsa X=TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128 CV=no A=dovecot_plain:[email protected] S=1698 [email protected] T="Re: Estimate 5356 from Country Glass Company Inc." for [email protected] [email protected]
2017-07-26 19:38:55 1daYhS-0006Ym-5l => stas <[email protected]> R=virtual_user T=dovecot_virtual_delivery C="250 2.0.0 <[email protected]> w3vLMT9SeVmZYgAAKB3gjA Saved"
2017-07-26 19:40:29 SMTP connection identification H=c-76-19-64-7.hsd1.ma.comcast.net A=76.19.64.7 P=33930 U=altreco ID=593 [email protected] B=get_recent_authed_mail_ips_entry
2017-07-26 19:43:15 SMTP data timeout (message abandoned) on connection from c-76-19-64-7.hsd1.ma.comcast.net (captain) [76.19.64.7]:33930 F=<[email protected]>
2017-07-26 19:49:02 SMTP connection identification H=c-76-19-64-7.hsd1.ma.comcast.net A=76.19.64.7 P=33931 U=altreco ID=593 [email protected] B=get_recent_authed_mail_ips_entry
2017-07-26 19:50:29 SMTP connection identification H=c-76-19-64-7.hsd1.ma.comcast.net A=76.19.64.7 P=33933 U=altreco ID=593 [email protected] B=get_recent_authed_mail_ips_entry
2017-07-26 19:50:29 1daYsf-0007WM-IK <= [email protected] H=c-76-19-64-7.hsd1.ma.comcast.net (captain) [76.19.64.7]:33933 P=esmtp S=634 [email protected] T="yes, tile sample is on site" for [email protected]
2017-07-26 19:50:29 1daYsf-0007WM-IK SMTP connection identification H=c-76-19-64-7.hsd1.ma.comcast.net A=76.19.64.7 P=33933 M=1daYsf-0007WM-IK U=altreco ID=593 [email protected] B=recent_authed_mail_ips_domain
2017-07-26 19:51:47 SMTP data timeout (message abandoned) on connection from c-76-19-64-7.hsd1.ma.comcast.net (captain) [76.19.64.7]:33931 F=<[email protected]>

 

[cPanelMichael]

Hello,

It's possible the "SMTP data timeout (message abandoned) on connection" error message stems from the following option under the "ACL Options" tab in "WHM >> Exim Configuration Manager >> Basic Editor":

Introduce a delay into the SMTP transaction for unknown hosts and messages detected as spam.

It's documented at:

ACL Options - Exim Configuration Manager

Could you have your provider temporarily add the IP address you are making the SMTP connection from to the Trusted SMTP IP Addresses section of WHM's Exim Configuration Manager interface to verify if that's the cause of the problem?

Thank you.

 

[Stas Burdan]

Thank you - will ask them to try it

 

[Stas Burdan]

From the hosting provider:

I have disabled the option to introduce a delay for unknown hosts and added your IP address 76.19.64.7 to the 'Trusted SMTP IP addresses' list. Please have a check on your end and write back to us with the results so that we can assist you further.


However, the problem did not go away. I found a message that failed yesterday and modified To: and Cc: list to only have my email address on To: list and no other email addresses. The message failed the same way it did yesterday. If I chop up the message and only send first few lines (random number of lines) to the same list, i.e. only my own email, SMTP works.

At this point I am convinced that the message body content, encoding or similar issue causes the problem with SMTP protocol.

I have been asking my hosting provider to describe what they did in the last week or so, as nothing changed on my side, however I am having difficulties getting it from them. I will try again.

If you have any further ideas on how to debug this - I would really appreciate it

Thank you

 

[cPanelMichael]

Hello,

You may also want to ask your hosting provider to open a support ticket with us using the link in my signature so we can access the system and take a closer look.

Thank you.

 

[Stas Burdan]

the hosting facility says that they did not have any major upgrades recently. And in the meantime the problem went away...

I honestly have no idea why. If it is indeed true, that no updates or configuration changes happen on their end, it must have been some other condition that they didn't understand caused the problem. I can't imagine it was anything on my end.

Anyway, thank you for your help

 

[cPanelMichael]

Hello,

Feel free to let us know if the issue comes back and you have additional questions.

Thank you.