SMTP2GO is mail delivery that just works.

I run a small email/phone/web hosting company and was forced into relocating my equipment to a new data center a couple of years ago. I'm a small enough operation that I don't have my own block of IPs so when I had to relocate I also got the joy of starting with a new block of addresses. Many other email systems do not like seeing a "new" IP that starts sending lots of traffic all at once so in order to maintain a high deliverability for my email customers I employed SMTP2GO for sending emails. They've done a good job with very few deliverability issues. Now that I've been using my new IPs for a couple of years they're considered to have a good reputation world-wide, but I decided to continue using SMTP2GO to send emails for the forum sites I host because of their excellent deliverability when it comes to what can sometimes be considered mass emailing (a single reply on a forum can sometimes trigger hundreds of notification emails to people who have subscribed to the thread). I'm happy with their service and would recommend them to anyone looking for reliable email delivery.