writing specs on a mailing manager/ newsletter application.
 

I"m working on a mailing manager/newsletter application. What are some analytical / statistical features necessary?

I was going to buy/lease, but the systems charge so damn much (most seem to be SaaS) and none seem to break out with amazingly distinguishing features.

http://www.mailchimp.com/features/full_list/

/\--- I've been looking at this one as a feature set, any other nice programs with interesting features?

I smell spam.

To clarify it is absolutely not for spam.
It's for an organically grown fully-compliant list.

Do you have any suggestions on good SaaS providers?

Any input on useful features?

um this is cool!!!!!

MailChimp just about covers all basis.

ConstantContact is another one worth looking into.