Add mailing support to #9112.

[marcoag]

Please note this issue can be taken by multiple participants. It will remain open and accessible to all participants until a successful PR is submitted.

WARNING: This is an issue for the new version v3 of the eventyay backend API, make sure you are working with the dev-v3 branch, and that your PRs target that specific branch.

Depends on #9112.

Add actual mailing support to the system. Set the form to configure the mail support and give the capability of emails from #9112 to be actually sent.

[techmannih]

hello @marcoag ,
can i work on this issue

[hpdang]

Please note this issue can be taken by multiple participants. It will remain open and accessible to all participants until a successful PR is submitted.