Test using smtp with public ipv6

[samaradel]

Work in Progress (WIP):

tested on:

• Discourse:

• Gitea:

• Mattermost

[samaradel]

Work in Progress (WIP):

had some mistakes made by me .. keeping testing and waiting for Ops to verify the provided SMTP server

[samaradel]

Work in Progress (WIP):

• I got back for Discourse and I found it supports ipv6 with specific configuration ... testing..
• Mattermost support ipv6 with port 465 and with TLS enabled
• Gitea needs 3 hours to make sure if SMTP is working and ipv4is still not working. debugging.

[samaradel]

Work in Progress (WIP):

• Gitea email testing not working, and I'm blocked on #289
• still searching for Discouse ipv6 supporting

[samaradel]

Blocked on #293 and #289