In their zeal to counter spam, both AOL.com and Yahoo.com - and possibly some other big players - changed their email reception policies which effectively cut off their customer's ability to receive emails from mailing lists which are configured in a VERY reasonable manner - in effect destroying uncounted thousands of email lists around the world.
Folks like me have been desperate to have our email lists restored to function, so tn an effort to address this, the mailman folks apparently pushed out a new version - very laudable. But, according to my web searches, many people are encountering a bug or bugs with this release, just like me.
When you encounter this problem, it's through the web interface and this is what the user sees:
Bug in Mailman version 2.1.18-1
We're sorry, we hit a bug!
Please inform the webmaster for this site of this problem. Printing of traceback and other system information has been explicitly inhibited, but the webmaster can find this information in the Mailman error logs.
Aside from having Yahoo.com and AOL.com behaving VERY badly, we now have this bug, too, and we need to figure out what to do about it. There is apparently a new bug-fix release out there specifically to fix this, but it's not ready for my platform yet and I'm not necessarily up to building it from sources just now. What a pain! If you do a web search, you'll find MANY people posting about their encounter with this problem, and, so far, I didn't find anyone post a solution.
...I'm no Python expert, but I was brave and started to try and diagnose the error. It didn't take me too long to suspect a file permissions problem. And, being bold, I tried a solution and it worked... I'll answer my own question below - just leaving bread-crumbs for others who may encounter this same problem.
