1243291 - Thunderbird v38.5.1 not using specified port, is using default port of 25 for Outgoing Server (SMTP).

Status: RESOLVED INCOMPLETE

(MailNews Core :: Networking: SMTP, defect)

Description

[MikeP]

Background info:
I've been using Thunderbird for so long I can't even remember how long, and I've been running with this specific config for at least 2-3 years.  Nothing special about the config for my outgoing SMTP server on my internal network, except for the fact that my SMTP server listens on port 2525 instead of the often default port of 25 (for unimportant reasons that I won't both explaining here).

The problem:
Never had any problems sending to port 2525 until I went to send an email today (using v38.5.1, which I think I updated to just a day or two ago), and I receive the "Send Message Error" as follows:

"
Sending of the message failed.
The message could not be sent because connecting to Outgoing server (SMTP) 192.168.0.2 failed.
The server may be unavailable or is refusing Outgoing server (SMTP) connections.  Please verify that your outgoing server (SMTP) settings are correct and try again.
"

So, I took a look at the outgoing SMTP setting and it looked fine (server=192.168.0.2, and port is 2525).

Next, I watched the server log as I attempted to send another email through it.  Same error, but nothing observed in the log files.

I opened telnet from my system to the server on port 2525 and the server responded as expected, and I saw log entries showing the same info...  It seems like Thunderbird isn't even trying to talk to my server.

I fired up Wireshark and captured packets while trying to send email to my server, and Wireshark showed my TCP connection attempts happening on port 25, not 2525 as specified under "Tools\Account Settings\Outgoing Server (SMTP)\Edit\Port"

I tried changing the port to other numbers besides 2525 and 25 (e.g. 75, or other random ports), but Wireshark always shows Thunderbird still only using 25, regardless of what I set there for the port to use.  I tried changing the IP address, just to make sure it was, in fact, using my default outgoing server entry, and when I changed the IP I got an error message with the different IP, so it seems it's using the default server like its supposed to, but just not changing the port.

Finally just to verify one more thing, I moved my mail server back to port 25 instead of 2525 and then I was able to send mail just fine.  So, for now, that's my work-around, but it looks like maybe someone hard-coded port 25 such that whatever you specify under the Outgoing Server (SMTP) settings is no longer respected.

Comment 1

[MikeP]

P.S.  Under Platform, I noted it as x86_64 (since that's what my system/platform is), but, in case it matters, I'm still just running the 32-bit version of Thunderbird.

Comment 2

[Wayne Mery (:wsmwk)]

rsx11m, Matt,

I don't know whether there are new SMTP/account related problems, but there have been several reported issues in the past year (more than normal?) - some confirmed invalid (like bug 1189000), and others like bug 1239019 indeterminate.  

https://mzl.la/2adxY2m are bugs citing smtp. We know from history that many end up closed invalid. But keeping an open mind, what do you think?

Comment 3

[rsx11m]

I don't have a comparable setup but connect to my server on port 587, which is a standardized port too (thus, 25 is not hard-wired in the code). I would expect autoconfiguration to fail, though.

MikeP, as a stupid guess, maybe there is another definition for the SMTP server which may connect to the default port of 25? I assume that you've verified that already in the Account Settings, but a way to be sure is to go into the Advanced options and click on Config Editor there. Filter the preference list on "smtp" and see if anything other than "mail.smtpserver.smtp1..." is defined. Also verify that mail.smtp.defaultserver points to smtp1 (or whatever the id of your server is).

Comment 4

[Matt]

I saw mention from Jorg that there is a problem with outlook hosted domains failing in the new account wizard due to the probing getting caught up with the outlook.com servers and DNS.  Trouble is I can not remember where or when.  But I have never heard of the designated port not functioning as asserted here.

Comment 5

[Wayne Mery (:wsmwk)]

reporter is gone so let's call this incomplete