Mass emailer program, better than entourage?

[Bill Morse]

Hello-

I am consulting for a non-profit, and am looking for a better solution for
group emails than entourage.  This is not a spam operation, but rather
communication with people who have signed up at our web-site or events.

We have a filemaker database, and often will need to send an email to about
4,000 addresses.  Currently this is done by creating a message in entourage
with 4,000 BCC's.  The problem is if one address is faulty (old, changed, or
simply mis-entered), the entire operation will come to a halt, and we don't
know if any messages have been sent, so we have to send the entire mass
mailing again- takes time, and worse, risks bothering some recipients with
duplicate messages.

Is there a better way to do this, either in OSX or 9.x?

Thanks in advance for any thoughts.

Bill Morse