Looking for mailing list, that allows HTML in welcome message (and stuff)

[toasty]

I'm looking for a mailinglist/newsletter script that does the following.
[code]
1) Easy integration into existing webpage.
2) Upon submitting subscription one or the other of the following happens:
2a) The user is edirected to a thank you page.
2b) The user receives a pop on the exiting page saying thank you (or something.)
3) Compose mass emails in either text or HTML
4) Allows HTML in the "welcome" email (the email that's automatically sent to the user's email after registering or confirming their email address.
[/code]
So far I have yet to find any script that does #4 above.  It seems most scripts offer either option #1 [b]or[/b] option #2 but not both.  I've spent probably about 23 hours over the past three or four days... what day is it now?  I'm freakin' dying here.  If anyone has any suggestions about a script that does all [b]four[/b] of the above I will be so completely totally greatful.

Thanks!