One of the sites that I work with just implemented a feature on their site that allows members to invite their friends to the site by importing their address books from Gmail, Yahoo!, AOL, Hotmail, and other email providers. This is a common feature on most social networks these days, and there are many scripts available with this functionality.

As soon as they implemented the feature, they were sending tens of thousands of email messages per day.  Some of the big email providers did not take kindly to their email practices (which were completely legitimate) and they were blocked from both Yahoo! and Hotmail within a week.

To help them in this situation, I was in charge of researching email deliverability consultants to help with the problem.  Although there are some standard technologies that can be implemented to help improve deliverability (Domain Keys, SPF, etc.) the whole process seems like black magic. Naturally, there are lots of consultants out there pitching their deliverability voodoo. I was amazed when I spoke with one of the leading companies in the space and they were looking for a retainer of $10,000 to $15,000 per month.  I am sure that they are good at what they do, but this seemed exorbitant to me.  After researching many options, I recommended that the company work with a consulting company on a three month engagement for a very reasonable $750 per month. The company has big name clients and a great deliverability track record. I will report back in a few months to let you know if they were able to improve the company’s deliverability.