Allow to define a FROM address for the send emails

[SiMaHer]

In the current implementation of this extension messages send to a mailing group are send to everyone with the FROM address of the address, that has send the email in the first place.
This is a great solution, if everyone, that sends emails to the mailing group has an email address within the domain of the mailserver.
However, this does not allow email addresses to participate in the mailing group, that are not part of the mailservers domains.
Therefore, it would be great, if there is an option to define a FROM email address for any email send to the mailing group with some indication, who send the email in the first place such as the topic of the email or something comparable.

[jensschuppe]

I'm not sure I fully understand your proposed solution, @SiMaHer. Could you put an example of what you'd like the extension to do?

[SiMaHer]

Thanks for the reply. I would like to be able to add contacts, which have email addresses of external providers such as Gmail or Posteo.
To my understanding, the current behaviour of the extension is to put the email-address of the contact, that initially wrote the email as the from-address of the email. If this is used with email-addresses of external providers, where the mailserver used by CiviCRM is not allowed to send emails, this would cause reputation problems in the long term.

[jensschuppe]

Thanks, @SiMaHer, for your explanation. That's indeed a limitation of some sort.

So you're suggesting to add a configuration option for a fixed from e-mail address in MailboxMailing Mail Settings entries, as already exists for configuring from e-mail addresses for notifications (bounce reports and "not allowed" notifications").

This should be easy to do, but we don't have any funding and/or time for doing that ourselves. Would you be able to provide a PR?