Why Self-Hosted Email Servers Beat ESPs

One thing in my email experimentation and quest to find the best email marketing solution has been clear:

Hosting your own email server beats ESPs - every time.

Even Mandrill, which I've raved about in previous posts, has fallen behind in seed-list deliverability tests.

Why?

Simple: When you use an ESP, your dedicated email IP address is sitting on a Class-C IP block with - you guessed it - over 200 mass mailers!

Self-hosting, on the other hand, puts you in much better - and more reputable - company. Especially if you're using a premium hosting company like Rackspace as I am. 

When I went to Cisco SenderBase to check reputation on my mail IPs, I dropped the IP selector to /16 to see who I'm sharing my IP block with. It looks like I'm in pretty good company. Some examples include:

- Edible Arrangements
- Kellogg's
- Fiverr
- NeilMed

Like me, all of these organizations have good mail reputations. With my Mandrill or Sendgrid IPs on the other hand, the results aren't so good. I'm sitting on an IP block full of mass mailers, many - or most - of whom are sending out spammy content to lists of questionable quality, and as a result they're getting the rest of us penalized.

The best example of this is Sendgrid. When I started using them in March, 2011, I saw an immediate bump in open rates and sales numbers, despite the high cost. Gradually that declined, and a recent series of seed-list tests shows them going to Hotmail/Outlook junk 100% of the time and getting blocked completely by AOL. When confronted, they tried to blame my content, despite the fact that this was not happening with my own IPs, or even with other ESPs.

Mandrill is another good example. Initially I saw almost impossibly good inbox rates with them, but they're sadly down below 70% now.

Why? Very simply because they've grown in popularity, they've added large numbers of new customers, and the end result is lots of spammy content coming out of their servers and their IP blocks. Sure, they can police their customers and suspend users who are spamming, but in the end, they have to make money which means looking the other way to a certain degree in order to keep enough billing customers on the books.

If you're intimidated by the prospect of maintaining your own mail server, don't be. I sent through my default localhost mail on my server for a long time (after adding SPF and DKIM validation of course) and then spent a few hundred bucks on a custom Postfix setup that consistenly out-performs the ESPs. And it's free - no monthly or per-email charges!

For larger senders, Postfix is still an option, and I've seen good results from GreenArrow Engine, and PowerMTA, although GreenArrow's support and customer service is infinitely better than that from Port25 Solutions, PowerMTA's parent company.