Email personalization

I have just finished a personalized mailing script that builds a
personalized multi-part mime during delivery against a list.
But I need to do it for thousands of emails.
I make sendmail calls from an external method and it is slow so I hope to
gain external power from Mailman.

We need to preserve this capability of creating and generating personalized
emails in Zope.  Is this in the plan?
One thought is to compile a payload and hand to Mailman. (payload compiled
from the list and the email itself per email address, XML-RPC to deliver the
payload if direct calls cant be made.)
XML-RPC also has the interesting implication that Mailman could be a remote
server with the list.  And Zope a remote server with the content.  I have
dealt with clients that  want to handle the delivery themselves, but want
content/email management services.

-Trevor