fix: allow SMTP TLS to be set for all ports

[leinelissen]

This reverts PR #40943
This resolves #45899

Basically, this allows for setting TLS settings on ports other than 465. If someone wants to use STARTTLS, they should set MAIL_ENCRYPTION to null and Symfony Mailer will automatically upgrade the connection if STARTTLS is available.

[taylorotwell]

So how does this not just put right back in the situation that people were saying was broken?

[leinelissen]

If you want I can add documentation that clarifies configuration for TLS and STARTTLS in the SMTP transporter. I've also looped in the author of the other PR to find out what the underlying problem was.

Regardless, I feel the current situation hurts SMTP configurability so I do want to propose this as a necessary change.

[leinelissen]

Alternatively, we can change the syntax so that it much more closely resembles how Symfony Mailer is currently setup. That requires more modifications and I think that would be a breaking change though.

[taylorotwell]

Can't merge this PR if we're just going back to something people were complaining about.

[leinelissen]

Would it be okay if I manage to convince the original author and verify it won't cause any issues for them?

[taylorotwell]

It wasn't just the original author - there were lots of people in that thread?

[taylorotwell]

Added this: 68a8bfc

[leinelissen]

Yeah that's perfect, thanks so much!