[Feature Request] Test-Email when setting up smtp

[weilBaum9]

It would be helpfull to have a way to send an email to an email-adress on the smtp/mailgun setup page.

Or any other way to test if the settings for sending mails were entered correctly.

[hrfee]

An easy enough way to tell is to just send your own Jellyfin account an announcement. I won't add an actual button for test emails but will mention this in settings.