Mattermost, Inc.

SMTP not working after 4.7.3

Summary

After the upgrade to 4.7.3 our Mattermost emails are not sending any longer.

Steps to reproduce

Currently using Mattermost 4.8.0 (smtp still not working) with postgresql 9.6 and nginx 1.10.3
Email worked fine before the upgrade to 4.7.3

Expected behavior

Mattermost should send emails and test emails as intended

Observed behavior

SMTP details are all correct and working on a different app. It’s just Mattermost where it doesn’t work. Tried to use different Connection Security options and change ports accordingly (25/587) which didn’t work either.

Before the upgrade it worked with
SMTP Server: mail.gandi.net
SMTP Server Port 465
Enable SMTP Auth: true
Connection Security: TLS
Skip Server Cert Var.: false

Trying to send a test mail shows error:
“Connection unsuccessful: Failed to open TLS connection”

Error Log for trying to send test mails:

[2018/03/19 11:13:56 +07] [EROR] /api/v4/email/test:SendMail code=500 rid=n4z89dx7mp85fjqmes67y5xqww uid=stee8rmw67ntzcjf9mueqoktmc ip=182.232.144.40 Failed to open TLS connection [details: dial tcp 217.70.178.9:465: getsockopt: connection timed out]
[2018/03/19 11:14:42 +07] [EROR] /api/v4/email/test:SendMail code=500 rid=o6ui938j3tgnjp9xbe3yfjtt1o uid=stee8rmw67ntzcjf9mueqoktmc ip=182.232.144.40 Failed to open TLS connection [details: dial tcp 217.70.178.9:465: getsockopt: connection timed out]
[2018/03/19 11:21:50 +07] [EROR] /api/v4/email/test:SendMail code=500 rid=hkcadqoi4br8fqmpjcz79zh53a uid=stee8rmw67ntzcjf9mueqoktmc ip=203.172.103.162 Failed to open connection [details: dial tcp 217.70.178.9:25: getsockopt: connection timed out]
[2018/03/19 11:27:35 +07] [EROR] /api/v4/email/test:SendMail code=500 rid=hh3y4e8bofdzfneaxetqxbccmo uid=stee8rmw67ntzcjf9mueqoktmc ip=203.172.103.162 Failed to open TLS connection [details: dial tcp 217.70.178.9:465: getsockopt: connection timed out]
[2018/03/19 11:38:18 +07] [EROR] /api/v4/email/test:SendMail code=500 rid=pfnioc39rfyjdgk6bn88drnxoh uid=stee8rmw67ntzcjf9mueqoktmc ip=203.172.103.162 Failed to open TLS connection [details: dial tcp 217.70.178.9:465: getsockopt: connection timed out]

Update:
telnet mail.gandi.net 465 doesn’t work any longer. Setting up smtp.gmail.com as alternative server with our gmail account credentials works for the time being, but it’s strange that another app/server can access mail.gandi.net with the same credentials we used for Mattermost in the past (while Mattermost can’t any longer)

Hi @Ju_St,

Perhaps this TLS documentation will help troubleshoot your issue?

Also including the SMTP email setup doc in case it’s useful…