mail_domain clarification re: SMTP EHLO

[monochromec]

☑️ Resolves

• Fixes misleading mail_domain config parameter description (cf. [Bug]: config parm 'mail_domain' is ignored when entering SMTP init phase server#43955 ).

[monochromec]

Fixed malformed link.

[tflidd]

I'd rather say that it uses the value of overwrite.cli.url. Because like that, you might get the impression to set this variable accordingly to make the mail delivery work. But it has other consequences as well (it's not use exclusively for the mail EHLO).

[joshtrichards]

This is already noted in the actual E-mail configuration chapter:

https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/email_configuration.html#configuring-an-smtp-server

Note

The overwrite.cli.url parameter from config.php will be used for the SMTP EHLO.

I don't think it needs to be included in the config.sample.php personally (as proposed in this PR) since it's a fairly obscure customization, but if one is going to do that... the config.sample.php in this repository is actually pulled from the server repository here. The PR would have to be against that.

[github-actions]

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