Implements #10012. RedirectAllMailto might optionally dynamically set by...

Implements #10012. RedirectAllMailto might optionally dynamically set by current logged in FE or BE User.

Documentation/Debug.rst

@@ -183,7 +183,7 @@ Redirect all mail to (catch all)
 
 Setup in :ref:`configuration`
 
-* *redirectAllMailTo=john@doe.com*
+* *redirectAllMailTo=john@doe.com[,jane@doe.com[,fallBack@doe.com]]*
 
   * During the development, it might be helpful to configure a 'catch all' email address, which QFQ uses as the final receiver
     instead of the original intended one.
@@ -194,6 +194,9 @@ Setup in :ref:`configuration`
     * Clear 'CC' and 'Bcc'
     * Write a note and the original configured receiver at the top of the email body.
 
+  * If more than one email address is given, QFQ compares all of them (in the order given) with the logged in FE and BE
+    User email address (which might be configured in T3). If a match is found, that one is the final 'redirectAllMailTo'
+    address. If there is no match found, take the last email address - this behaves like a fallback.
 
 Show log files realtime
 -----------------------