I've been told by an ISP that messages from my mailing list are addresses to too many people so it gets kicked by their spam filter.They said the limit is somewhere between 20 and 25.
At my previous host the mailing list program had a setting where I could adjust the number of addressees on each mail. So if I 100 people on my list and I set that limit to 20 it would send 5 messages of 20 each.
I don't find a similar setting in Mailman. Any suggestions?