[Pkg-exim4-users] exim4 stopped sending mail after upgrade from Buster to Bullseye

[Gary Dale]

On 2021-08-22 16:52, Gary Dale via Pkg-exim4-users wrote:
> I've done some testing using smtp-cli and it seems to work. I never 
> get the e-mail, but it seems to have succeeded to making the 
> connection... Here's the session, starting with the command and 
> including entire output (only my customer's domain name has been removed)
>
> smtp-cli --verbose --host=web71.dnchosting.com --enable-auth --user 
> sendmail@<one of my domains> --from sendmail@<one of my domains> --to 
> gary at extremeground.com --data /etc/exim4/test.text
>
> Enter password for sendmail@<one of my domains>@web71.dnchosting.com :
> Connection from 192.168.1.17:50520 to 192.64.150.71:25
> [220] 'web71.dnchosting.com ESMTP Exim 4.94.2 #2 Sun, 22 Aug 2021 
> 16:18:30 -0400 '
> [220] 'We do not authorize the use of this system to transport 
> unsolicited, '
> [220] 'and/or bulk e-mail.'
> > EHLO localhost
> [250] 'web71.dnchosting.com Hello 
> cpe0018e7d3134a-cmf81d0f8158d0.cpe.net.cable.rogers.com [99.248.170.28]'
> [250] 'SIZE 52428800'
> [250] '8BITMIME'
> [250] 'PIPELINING'
> [250] 'PIPE_CONNECT'
> [250] 'AUTH PLAIN LOGIN'
> [250] 'STARTTLS'
> [250] 'HELP'
> Starting TLS...
> > STARTTLS
> [220] 'TLS go ahead'
> Using cipher: ECDHE-RSA-AES128-GCM-SHA256
> Subject Name: /CN=web71.dnchosting.com
> Issuer  Name: /C=US/ST=TX/L=Houston/O=cPanel, Inc./CN=cPanel, Inc. 
> Certification Authority
> > EHLO localhost
> [250] 'web71.dnchosting.com Hello 
> cpe0018e7d3134a-cmf81d0f8158d0.cpe.net.cable.rogers.com [99.248.170.28]'
> [250] 'SIZE 52428800'
> [250] '8BITMIME'
> [250] 'PIPELINING'
> [250] 'PIPE_CONNECT'
> [250] 'AUTH PLAIN LOGIN'
> [250] 'HELP'
> AUTH method (PLAIN LOGIN): using LOGIN
> > AUTH LOGIN
> [334] 'VXNlcm5hbWU6'
> > c2VuZG1haWxAcm9zc2xhbmQuZGVudGFs
> [334] 'UGFzc3dvcmQ6'
> > VGVycmlibGUyc2hvVXNl
> [235] 'Authentication succeeded'
> Authentication of sendmail@<one of my domains>@web71.dnchosting.com 
> succeeded
> > MAIL FROM:<sendmail@<one of my domains>>
> [250] 'OK'
> > RCPT TO:<gary at extremeground.com>
> [250] 'Accepted'
> > DATA
> [354] 'Enter message, ending with "." on a line by itself'
> [250] 'OK id=1mHtvL-0001x5-4I'
> > QUIT
> [221] 'web71.dnchosting.com closing connection'
>
>
> When I send e-mail through exim4, it simply stays in the queue. I'm 
> not seeing any error messages in the exim4 log 
> (/var/log/exim4/mainlog) other than ones saying the mail is still in 
> the queue (retry limit not reached).
>
> I have another (working) server (in a different location) that I also 
> upgraded a few days earlier with identical (AFAICT) configuration 
> except for some names & passwords (different smarthost and accounts 
> with a different hosting company). When I try using those names 
> instead, it still doesn't work. Yet this other server is sending me 
> e-mail just the way it always did.
>
> Clearly there is a difference in the two setups but I can't see it. 
> smtp-cli was my attempt to debug the problem but since it seems to be 
> working, I'm stumped. Can anyone suggest something I can try to find 
> the problem?
>

I noticed that the difference between the two servers was that I'd not 
accepted the new template (exim4.conf.template) on the server that still 
worked but that I had in the one that broke. When I replaced the 
template on the working server, it also broke.  I did make a couple of 
modifications to the old template (as I recall, to handle StartTLS or 
smtps) but copying them into the new one didn't help. Reverting to the 
old template fixed the problem.

The new template seems to be a lot larger than the old one. Something in 
it kills my working connection to two different smarthosts.