Correct SMTP port number

[mikeashley]

Port 587 for smtp does not appear to match the mailserver configuration and leads to incorrect autoconfiguration. Changed to 465 and tested with Icedove.

[neuhaus]

I don't agree with this pull request. Port 587 is correct, it is the submission port, designed for authorized mail clients (RFC 6409)

Wikipedia states at https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol

"Although some servers support port 465 for legacy secure SMTP in violation of the specifications, it is preferable to use standard ports and standard ESMTP commands according to RFC 3207 if a secure session needs to be used between the client and the server."

[mikeashley]

When deploying on Debian 7, postfix listens on 465, not 587. Roundcube is configured to submit to 465 as well. Are you suggesting changing the configuration of postfix and roundcube instead? Is this a Debian-only problem?

[lukecyca]

This PR makes sovereign consistent with itself (using port 465 throughout), so it's merge-able.

I agree that 587 is more correct and that we should switch to it. @neuhaus, could open an issue to that effect (and submit a pull request if you are inclined).

[taoeffect]

I closed our corresponding issue in Empress because STARTTLS is less secure that SSL/TLS, and apparently it's "required"? for 587 (or that's the purpose of that port).

The "correct" answer in that serverfault link is bunk. He's looking at it from the perspective of server-to-server communication which is crappily secured atm, but for client-to-server communication STARTTLS does nothing.

So, I recommend closing this issue here as well.

[taoeffect]

Updated comment above to add this link re port 587 and STARTTLS: https://stackoverflow.com/questions/15796530/what-is-the-difference-between-ports-465-and-587

[neuhaus]

1. the roundcube connection is on the loopback interface so even if it's not encrypted, there's no issue
2. server-to-server SMTP always uses port 25, that's not what this issue is about
3. clients should be configured to force TLS on. If STARTTLS gets stripped by an active attacker on port 587, it will get noticed right away.
4. port 465 is deprecated

[neuhaus]

I'll open a separate issue about this so this issue can be closed