I was having that problem with Yahoo accounts (and I have A LOT of Yahoo subscribers
) - - so I recently made the switch to AWeber. This was recommended to me by Mike Merz (I said, "Mike - Help
" - he said "AWeber - its what all the big guys use"... 'nuff said
).
It's 19.95/month - which, yes, I balked at to begin with (considering I had been using a free script). But I have to say, its been worth every penny. You have extensive tracking capabilities, everything completely automated of course, and my emails actually make it to their destination now. I'm able to tell where subscribers come from - specifically (not only which site, but which page on that site!), how many emails were delivered, how many undeliverable - you can even track how many of your emails were *opened* and which links were clicked on... Good stuff
They do have a free trial if you want to test it out:
http://www.selfstartersweeklytips.com/aweber.htm