Originally Posted by DoubleD

Hey Petra, yea there are 3rd party ESPs out there that will do the sending...to be honest everyone of the big ones have adult clients...they generally keep it hush hush a bit, but it happens and often enough...but they'll be interested in volumes, how old the list is in general, etc, etc

This is a topic I know a heck of a lot about...a growing list can sometimes be a double-edged sword depending on how you handle list hygiene - yahoo in particular can be dufficult, many large mainstream senders have the same issues with yahoo. Consider the idea of "engagement" - many of the big, free ISPs have moved to looking at this, how engaged are the receivers on your list in general - ie old, inactive emails, how engaged are they for your particular sending - open rates are often used here as click thru rates can be misleading when looking at sending reputation.

If you have the ability to remove folks that just never open or click your messages do it, or in the last email above the fold place a warning saying "hey you're about to miss out on all these awesome offers, click here or this will be the last you get, yadda, yadda, yadda - a re-engagement campaign.

Its actually good to run this way, do re-enagement campaigns on a regular bases (not too frequent)...old emails, even addys older than a year have the potential to become spam trap addys...