Add support for Mailpit as the mail trapping solution

[bap14]

Mailhog is effectively unmaintained / abanonded. While it does still work it being unmaintained increases risk of issues arising as it ages, and any security vulnerabilities unpatched. The maintainer of Mailhog has self-admitted they don't have time for it anymore (see mailhog/MailHog#442 (comment) ).

The suggestion is to switch to the successor Mailpit. It is a fork of Mailhog, kessp the same interface, but generally keeps it working and updated (last release was June 22, 2024). It still provides its own sendmail client, and can be used as an SMTP client. The port values are even the same. It's a literal drop-in replacement (similar to MariaDB for MySQL).

I've created a PR that does this PR#779. It will add a new environment variable called WARDEN_MAIL_SERVICE which takes one of two values: mailhog or mailpit. By default it sticks with mailhog. A user can edit the ~/.warden/.env file to specify the environment variable with a value of "mailpit" to start using Mailpit instead.

[bap14]

This also adjusts the hostname for the service to be webmail.warden.test so it's one host regardless of service used.

[sprankhub]

1. I vote for replacing it completely. We have enough configuration already :D
2. IMHO, webmail.warden.test should be the new default and mailhog.warden.test should redirect to it for backwards compatibility.

[navarr]

2. IMHO, webmail.warden.test should be the new default and mailhog.warden.test should redirect to it for backwards compatibility.

That's a good thought and I agree completely. It will require a second traefik router and service added to Mailpit though; but I suppose thats fine.

[bap14]

When I have time (should be some time soon), I'll try and incorporate this feedback. Thanks!

[navarr]

@bap14 Appreciate ya!

[bap14]

@navarr @sprankhub Updates made. Mailpit now replaces Mailhog, and going to mailhog.warden.test 301 redirects to webmail.warden.test. Not sure why I need to format the yaml labels list using the object notation, but it wouldn't redirect otherwise.