We provide Email Marketing service through our online Application. We have about 30 customers. And each one has it's own mailling list (5k to 100k emails each).
We have a great application/product like MailChimp or CampaignMonitor but we fail providing a great service when it comes to inbox deliverability and high volume sending performance.
We do suspend customers that reaches 10% bounce rate to prevent our customers from using NOT opt-in lists.
Our lastest solution was to change our mail server's outgoing IP every few minutes using 100 IPs. But that does not works. That is not the solution Cloudsmtp.com or smtp.com uses.
Let's say we have a 5 milions deliveries per month ( we still not there )
Do we need more servers? or we could setup multiples MTAs in one machine? Can someone point me documentation on how to write a customized MTA that could control the outgoing mail flow preventing reaching Gmail, Yahoo and Hotmail rate limits?
Check this link bellow, because I think this is what I'm looking for http://blog.deliverability.com/nicolas_toper/
