Mailman: Setting the number of addressees?

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?


It is a discussion list.

I appreciate your help. I’m sorry if I’m not phrasing my question well. I do have a Dreamhost discussion list already set up. I referred to it as “Mailman” because that appears to be the program behind Dreamhost’s discussion list option. This list is getting rejected by a regional ISP because it’s distribution list is greater than 20.

I need it to chunk the email it sends to less than 20 recipients. This was a feature of my old mailing list provider (prior to Dreamhost) but I can’t find a similar setting in the Mailman admin section.