Holy Schmoly Robert - this was it for me, thank you for this post! This is very unfamiliar territory for me (the virtual host stuff) and I had to do some self-teaching before I could follow where to put the lines of code you referenced. But the internets are replete with examples and I'm a quick learner so for others who might be complete virtual host newbs like myself, here's a little more detail on how I applied this fix to resolve the 403 Forbidden error I was getting:
(after making sure the archiver keys matched and the base url was set to my actual domain and my ip was added to the MAIL_FROM variable)
The mailman3-full install for Debian provides you with an apache.conf file (in the deployment folder) and creates a symbolic link to it in the apache virtual hosts configuration folders (etc/apache2/conf-available). So that is nice - that is already taken care of.
What I wasn't sure about was where to add the new
I created the section at the top and just added the 2 lines to it for ServerName and Include, and a note to explain why it was there. After saving the file and exiting, I reloaded apache2.
What a nice surprise too that all 6 billion test messages I sent trying to get this to work showed up in the archive! :-) And actually that WAS a nice surprise because this is a live and active server and several messages had already come in since I deployed it this morning so those are now in the archives as well.
Time to go play outside. Happy first day of summer to all!
~Kelly