[Mailman-Users] Erratic mail delivery times

Peter Shute pshute at nuw.org.au
Mon Jul 21 07:06:05 CEST 2014

Mark Sapiro wrote:

> > Is limiting normally applied strictly per recipient? Or 
> does it reduce the problem if lots of the members are on one 
> domain? 50% of our members are with just 5 domains.
> It depends on the specific service and their policies. They 
> could limit recipients or SMTP transactions. If they limit 
> recipients, there's not much you can do.

I think they said it was a recipient limit.

> If the limit is on transactions, you can leave Mailman's 
> default settings for SMTP_MAX_RCPTS (500) VERP (No) and 
> personalization (No) and Mailman will group domains into a 
> few transactions with many RCPTs and this may help.

I don't think we'd have access to those settings with cpanel anyway, would we?

> But the question remains. If MTA rate limiting is the answer, 
> why did it only start not long ago (In one post you said 11 July).

They claim we were sending spam, and they noticed a huge spike in the amount of SMTP traffic (2.5GB vs the usual 10MB or so) on the 10th. they didn't show us stats for the numbers of emails, only the size. We think someone somehow hacked our account and really was sending spam, although we've only got their word for it. If they were sending it to list members that would explain the mail rejections I was seeing in my own logs.

Anyway, it's obvious that the topic of these limits is an old one, and the only new thing here is that we somehow got lucky and they didn't apply them for a long time. I think I'd have prefered if we'd known from the start. Time to concentrate on moving to a new provider.

Peter Shute

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