Emailing solution

I need a way to send emails that come in from the craigslist ads I post. I only do about 2000 - 3000 emails per night. Its not an email list or opt in, but not technically spam. These do need to be answered as they come in, not all at once later on, so if you cant do this please dont respond.

Basically I use an Smtp service right now but due to complaints he gets from multiple customers about spam, he has to shut down in August. I was considering a VPS or just rotating a few different shared hosting smtp services. Im not really sure the best way to go about doing this. I would pay well, probably even on a month to month basis, for a knowledgeable person to set this all up for me, and to keep it running making sure its hitting inboxes, rotating IPs if necessary ect.

PM me if you can help, thanks