Disposable Email Addresses

I recently had a couple of users signup and download a white paper and my follow up email to the same users the very next day started bouncing from the id. The strange part was that in spite of a double opt-in registration mechanism in place, I seem to have ended up with email addresses that were valid at sign up but invalid soon after.

A little bit of googling on the domain name of the email addresses led me to
mintemail.com. They offer a nifty little service to it's users where they offer a disposable email address that's valid for 4 hours.

From a B2B marketers perspective this is a nightmare scenario as the Lead Capture campaigns could be capturing worthless contact info that expires in a few hours time.
It sure is a boon to someone who'd like to access whitepapers, surveys, case studies, podcasts...etc of a company anonymously.

Maybe it's time the email validation routine in the registration form also validates for domain names known to host disposable email addresses.

Tar-pitting

"Tarpitting" also known as 'Teergrubing' is a way of reducing spam or spam-related attacks (such as directory harvesting). It involves delaying SMTP communications with remote servers suspected of sending unsolicited e-mail. This slows down the the automated email sender threads of spammers as they are forced to spend more time to send out the email and in some cases give up all together as their session timesout.

There are a lot of variants of this, some servers might tarpit based on sender reputation, while others look out for number of concurrent connections made, number of recepients addressed in the RCPT TO field of the same connection etc.

Metrics which show the average smtp session time and number of time smtp session timeouts per email domain might be a good way to find out if you are being tarpitted by a particular domain.

Optimal Send Time of Your Email

When is the best time to send out your promotional email?

I'm sure you would have done your research and know the latest recommended weekly optimal email send time slots, but so does every other e-marketer and SPAMMER. Infact your email could end up competing with scores of other commerical email's send at the same time slot.

So why not make this process customer driven and give your customer the choice of 'opting their preferred email send time'? You could find their preferred time in the following ways

1. Ask your customer when they subscribe (Direct)
2. Conduct an email/web survey to find out (Direct)
3. Find previous mail open time from email open metrics (InDirect)

So you'd have to add another segment criteria based on 'preferred send time' to ensure your emails reach your customers at their preferred time.

Reputation Filtering

Ever wondered why your carefuly crafted email devoid
of any 'spammy phrases' still fails to reach it's recipients?

According to a report published by ReturnPath 

"83% of the time Sender Reputation is the root cause for Email non Delivery"

       ISP's use eMail firewall/gateway servers like
BrightMailand IronPort to do reputation filtering
upfront before content filtering. The table below 
indicates the amount of reputation versus content
filtering done by ISP's

The results of the study indicate that reputation is the most
valuable asset of an eMarketer and needs to be safegaurded at all costs. So please think twice beforeyou buy a list or SPAM someone.

Worried about your reputation?
Find out if you have been black listed at  http://lookup.uribl.com/