In every one of your MailChimp campaign reports, there’s a section called Email Domain Performance:

It can answer important questions like, “Are any ISPs blocking me?” and “Which ISPs do my subscribers use most?”

It can also answer expensive questions, like, “Should I invest in email certification services like SenderScore (which gives you some benefits with Hotmail, Roadrunner, and Cox), or Goodmail (which gives you some benefits with AOL, Comcast, and Yahoo), or SuretyMail (which works with AOL, Yahoo, Hotmail, Earthlink among others)?

Email certification can get email past spam filters and into inboxes with images on by default, and in some cases, video will work.

But are they too expensive? Why not test? Here’s how:

For your next campaign, segment your list by an ISP domain, like hotmail:

(the segmentation screen is also a nice way to see what % of my list is actually using hotmail)

Send your campaign to this segment of Hotmail recipients. Do the same for AOL, Comcast, etc. if you want.

Log back in to MailChimp.

Check your ROI for each segment (you’ll need our e-commerce360 or Analytics360 plugins turned on):

Now you’re armed with actual data that you can use to determine how much each domain is worth to you.

Go talk to the email certification services to find out how much it’ll cost to implement for your organization and list size  (your annual email delivery volume is usually the factor), and what kind of improvement in open/click rates you might see for each domain.

Look back at your domain performance:

If you could get x more opens or clicks out of y domain, how much might that add to your bottom line?

I got this tip from Anna Billstrom, who has consulted for some really, really big companies (think mainframe computers) and writes a nice blog called Adventures in Email Marketing.

P.S. SuretyMail says they work with spam filters like Postini and Spam Assassin. Is it worth it? Why not check your campaign spam filter scores, with MailChimp’s Inbox Inspector?