smtp_server: Environment variable for changing outgoing port?

[lagerstrom235]

Today I was troubleshooting why outgoing mail wasn't transmitted.
Testing "telneting" to smtp.gmail.com ports 25 and 465 the issue became obvious, my ISP does not allow outbound requests on port 25.
Giving them a call confirmed this and also confirmed that they do not have any other way of allowing self-hosted servers to send mail, EXCEPT using another port.

Looking through the documentation, old issues and discussions and searching the web I was not able to find a solution for my problem, although I found a lot of people with the same issue.

My suggestion of a solution is perhaps an array of ports to try?

Configuration would look something like this: outbound_ports: [465, 587, 25]

This way mail would still be delivered even if port 465 or 587 isn't available/ refused outbound messages would still be delivered.

If this is something that isn't prioritized please let me know if you would accept such a PR.

In case anyone finds this thread when looking for a solution, please feel free to press the "up"-arrow so me and the contributors know this is a feature a group of people want, and not just me.

English is not my native language; please excuse typing errors.
Kind regards,
Ludvig

[willpower232]

its certainly something people have been interested in so worth a PR for visibility for sure

does your server provider allow you to receive emails? might be worth confirming with them just to be sure

[lagerstrom235]

Sure, I was going to call them today anyway.
I can telnet to my server on ports 25 and 465 so I don't think this is an issue.

The reasoning I could find around not allowing port 25 outbound is that the ISP doesn't want their IPs associated/blacklisted/blocked by customers sending spam.

The representative I talked with yesterday seemed to have other stuff on his mind while speaking with me so perhaps I'll get another answer today.
Hopefully I can get some better insights into what ports, why and how, so I can get a better insight to the issue they're trying to avoid.

I'll look into creating a PR when I get time.