I followed Kelly's guide and ran into some issues but were able to resolve most of them. It seems I have one out standing issue: Hyperkitty. When I post to a list, I am getting the following in the /var/log/mailman3/mailman.log:
Apr 11 14:01:15 2019 (1334) HyperKitty failure on http://localhost/mailman3/hyperkitty/api/mailman/archive: <!DOCTYPE HTML PUBLIC "-//IETF/$ <html><head> <title>503 Service Unavailable</title> </head><body> <h1>Service Unavailable</h1> <p>The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.</p> <hr> <address>Apache/2.4.29 (Ubuntu) Server at localhost Port 80</address> </body></html> (503) Apr 11 14:01:15 2019 (1334) Exception in the HyperKitty archiver: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>503 Service Unavailable</title> </head><body> <h1>Service Unavailable</h1> <p>The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.</p> <hr> <address>Apache/2.4.29 (Ubuntu) Server at localhost Port 80</address> </body></html> Apr 11 14:01:15 2019 (1334) Traceback (most recent call last): File "/usr/lib/python3/dist-packages/mailman_hyperkitty/__init__.py", line 154, in _archive_message url = self._send_message(mlist, msg) File "/usr/lib/python3/dist-packages/mailman_hyperkitty/__init__.py", line 210, in _send_message raise ValueError(result.text) ValueError: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>503 Service Unavailable</title> </head><body> <h1>Service Unavailable</h1> <p>The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.</p> <hr> <address>Apache/2.4.29 (Ubuntu) Server at localhost Port 80</address> </body></html>
Everything else works fine. Postfix is receiving and delivery mail to Mailman3. List members are receiving the posts. I can access the list on Hyperkitty just no archived messages.
Mailman 3 was installed using the mailman3-full package on Ubuntu 18:04 as per this walkthrough by Kelly.