I'm currently running Mailman 2.0.13 with sendmail on a PII/450 Linux system. My Mailman usage has been light and small lists. Now, my internal clients wants to send a mailing to 50,000 users (yes, they're opt-in!). What gotchas do I really need to be aware of? Initially, this first large batch will go to users of which over 90% are on the same domain (a customer of ours). How large are the mailman batches? i.e. How many physical mail messages go out? Can anybody take a wild guess as to how long it will take to ship that many messages out? What if the e-mails were distributed over 20 domains? What happens then?

Am I suicidal for even trying to handle lists this large on this size box, or is this even considered a large list?

Next, my users want the ability to periodically refresh the subscriber list - they'll actually be coming from an external database. At the time of my subscriber refresh, how can I flush any pending messages to the list - ie, I don't want to get caught where an earlier message is still being retried when the subscriber list changes. Is there a safe, recommended way to handle this?

All communications on this list will really be one-way; we send the messages out, but nobody can reply (and I realize that some people will try anyway).

Thanks, .../Ed

Ed Wilts, Mounds View, MN, USA mailto:ewilts@ewilts.org