I am a user of DirectResponders.com. I had an autoresponder meltdown in the middle of a launch where my autoresponder would send out unlimited duplicate emails, I would have to manually kill the job to stop it from sending. Needless to say I started getting un-subscribes.

I tried a free responder from DirectResponders.com and liked it so much that I upgraded for a years worth of service.

I have never had any of my emails blocked, they all get through and the system is very easy to use.

My 2cents

Al Andrews