How to let a docker container(or any anything) send mail through my mailserver?

killbotvii

There are a large amount of applications that support using an smtp server to send things like reminders and registration confirmations. The most recent example I’ve encountered is Vikunja, whose environmental variables for it look like this:
VIKUNJA_MAILER_ENABLED: 1 VIKUNJA_MAILER_FORCESSL: 1 VIKUNJA_MAILER_HOST: smtp.gmail.com VIKUNJA_MAILER_PORT: 465 VIKUNJA_MAILER_USERNAME: youremail@gmail.com VIKUNJA_MAILER_PASSWORD: Y0uRp@55W0rD!

My question is, what do I need to change in this to properly set this up? I created a mailbox for it and entered relevant information, but it didn’t work. The following is what I tried(censored the password):
VIKUNJA_MAILER_ENABLED: 1 VIKUNJA_MAILER_FORCESSL: 1 VIKUNJA_MAILER_HOST: mail.blairtech.org VIKUNJA_MAILER_PORT: 465 VIKUNJA_MAILER_USERNAME: vikunja@blairtech.org VIKUNJA_MAILER_PASSWORD: Y0uRp@55W0rD!

EDIT: Just want to add that my mailserver is in a VPS, while everything else is hosted on my homeserver.

killbotvii

I can’t edit the OP anymore for some demented reason, so…

EDIT 2: The following are two errors I noticed in Vikunja’s log, perhaps they offer insight into what I’m doing wrong?
2021-09-15T13:44:43.969280914Z: ERROR ▶ v1/UserTOTP 0c3 Totp is not enabled for this user

2021-09-15T13:44:55.335976988Z: ERROR ▶ mail/func1 0d8 Error during connect to smtp server: %s dial tcp: lookup mail.blairtech.com on 127.0.0.11:53: no such host

Do these relate at all?

killbotvii

What a horrible site this is, preventing me from editing my posts.

EDIT 3: I’ve solved part of the issue. It had to do with malformated env variables as well as including https:// in the mailing host entry, but now I’m seeing a new error.
2021-09-15T14:03:30.766912435Z: ERROR ▶ mail/func1 0d1 Error during connect to smtp server: %s dial tcp: address https://mail.blairtech.org:465: too many colons in address
It’s automatically adding everything after the .org, very confused as to why.

killbotvii

Give me permission to edit my posts and there won’t be this spam here.

EDIT 4: I’ve located the third party apps section of the documentation, but all of it assumes that everything is running off the exact same server. I’m seriously unsure as to how to adapt any of them(gitea, Nextcloud, portainer) to work with having mail hosted on one server and everything else on another.