the best ISP mail server solution ?

[Brent Bailey]

Hello,
I work for a growing ISP in the NE area. We are getting ready to plan a
build out of equipement to better provide email & web services to our
customers.

I was wondering what would this mailing list would recommend for a email
server software for up to 75,000 user capicity . Currently we have 20000 +
customers ..but i would like to plan for growth for over the next 5 years.
we have been growing at the rate of around 8000 users a year. Also the
need for webmail , spam & virus filtering is a must

I have in the past used sendmail & popper & imap-uw  & squirrelmail w/
Freebsd and have had GREAT luck but this is with a much smaller customer
base.

all help and or advise is GREATLY appreciated

thank you
-- 
Brent Bailey CCNA
Bmyster LLC
Computer Networking and Webhosting
Network Engineer, Webmaster, President
http://www.bmyster.com
mrb at bmyster.com
207-247-8330