What would anyone recommend as a good mailing list program to integrate into Outlook 2003/2007?  I have a customer thats currently BCC'ing in lots of 30-40 but I would rather they have something that sends individually overnight or something - Ive used Act! in the past and didnt like it one little bit.  Ive also used a program that does it based on mailing lists in Excel but they already have the lists made in outlook and I dont particularly want to be trying to teach them to export their mailing lists.  Any suggestions would be great.