[Mailman-Users] Postfix/Mailman breaks (somewhat) upon sending out to list of 300+ users

[Ted M Harapat]

Hello all. Any suggestions and ideas on this problem are welcome.

First of all, I recently switched to postfix after many years with sendmail and 
qmail. I really like it. So then I got majordomo working with it, then someone 
suggested I try Mailman and I really love this system. Thank you FSF & Python!

So it's easy enough to set up with a little looking around. I set it up and set 
up 4 lists on it. 3 of them with under 20 people on it, and one (for my father) 
over 300 people. The smaller lists work perfectly. That is, until my father 
sends out to his list of 300+ people. According to the mail logs, the incoming 
mail to the server is received to the list and it is sent back to my father for 
approval (as I have set it up intentionally). So he approves it, and it sends 
emails out to exactly 53 of the 300+ members. Then it stops sending with no 
errors (I've checked all of postfix's and syslog's logs). Not only that, but 
everything else with Mailman is then foobarred. Now when any of the smaller 
lists send to it, postfix records receiving it but then it doesn't do the next 
step such as sending it out to the users on the list or going to the admin for 
approval. It (Mailman) just stops dead cold. No more outgoing traffic or errors 
explaining why. 

So, upon examining every log I could think of, I finally just Reload postfix 
using the included scripts. Then, all of a sudden, everything starts 
processing. All mail waiting to go to the admins for approval or waiting to go 
to the end users on all the different lists are suddenly sent out as quickly 
and efficiently as everything normally goes with Mailman. All mail except the 
remaining 240+ people on my dad's list. Mail to those listmembers has 
disappeared.

So.... I decided to try this again. Same thing. Dad sends mail out to the list, 
it goes to exactly 53 people and dies again, and makes Postfix go goofy again. 
Outside of this combined Postfix/Mailman problem, the mail server acts as 
normal, processing all other traffic. I almost suspect that this is much more 
of a Mailman than postfix problem. I think I'm good enough with postfix to know 
if its a problem there and it doesn't appear to be. But I can't be sure because 
it is partially resolved just by my reloading the MTA. 

Strangely enough, these 53 users are the exact same 53 from the first time. 

I've checked over mailing lists for the last few months reading a lot of things 
(since what an email of this subject would be called) and didn't find anything. 
And nothing on this is in the FAQs or Manuals that I can tell. 

Anyone have any idea? Anything at all? 


HELP! 


-ted