Improve E-Mail Handling - Add errors for BCC and deliver CC

What does this MR do?

When receiving a mail with BCC to @foodsharing.network it is not possible to determine the mailbox reliabele. mailbox.org is adding the catchall@foodsharing.network as "Delivered-To", what is not mappable to a fs mailbox.

Now a error message is also sent in the cases where no recipient is found.

As currently there are mails lost, this should be deployed as hotfix.

TODOs:

• Check handling of internal BCC Mails
• Attach send mail to error message
• Add Hotfix date to Changelog

How confident are you it won't break things if deployed?

Quite Sure

Links to related issues

https://yunity.slack.com/archives/C1T1ZM9A4/p1708107129051729

How to test

Not testable currently

Screenshots (if applicable)

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• set a "for:" label to indicate who will be affected by this change
• added to the next milestone (see https://gitlab.com/foodsharing-dev/foodsharing/-/milestones, unless it has a "for:Dev" label)
• added an entry to CHANGELOG.md
• added a short text in the release notes to /release-notes/YYYY-MM.md
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/region?bid=734&sub=forum. Please change the MRs label to "state:Beta testing".
  • Consider writing a detailed description in German.
  • Describe in a few sentences, what should be tested from a user perspective.
  • Also mention different settings (e.g. different browsers, roles, ...) how this change can be tested.
  • Be aware, that also non technical people should understand.