I'm wondering which MUA (or method) is the best one to send out large
announcement mailings, which will respect the layout/format of e-mail and
respects the RFC's. For example, within my company we use Lotus Domino and
I'm curious when I initiate a distribution from a Lotus Notes client,
recipients will be able to read the content as meant. Also I'm interested
in the combination of sending out a mailing in both HTML as in plain text
format.

Any suggestions?

Michael Medenblik