How to Increase E-Mail Deliverability

If you're like me, you're finding that even permission-based e-mails have a hard time getting to recipients these days. Why? In order to protect themselves -- ourselves -- from the onslaught of spam, ISPs and subscribers are erecting an increasing number of barriers that seriously affect e-mail deliverability.

As an e-mail publisher, I see e-mail deliverability of my double opt-in newsletters deteriorating. Recently I read MarketingSherpa's new Permission Emailer's Guide to Avoiding Filters by Jill Deogh (www.wilsonweb.com/afd/sherpafilter.htm). Her 84-page e-book is by far the best and most practical work I've read to help e-mailers achieve better deliverability. It convinced me to take several new steps to protect my list investment. In this article I'm going to summarize some of her findings, but I strongly urge you to read the full e-book yourself.

Here are the various technologies being used to block delivery. The better you understand them, the better you'll know what you need to do.

1. Rule-based Filters. These monitor incoming e-mail for words and phrases common to spammers, for blacklisted IP addresses, etc. Examples: SpamAssassin and McAfee Spam Killer.
   
   

   Incidentally, would you be willing to take a quick 4-question survey about your take on spam and spam filters? I'd appreciate it. http://www.surveymonkey.com/s.asp?u=78266309203

    

2. Collaborative Filters. Communities of users report individual e-mail messages as spam -- sometimes carelessly -- and then produce a list of known spam messages. Example: Cloudmark SpamNet (which, incidentally, I use constantly myself).
3. Blacklistings. Self-appointed vigilantes publish lists of bad senders, but provide no accountability or ways of correcting errors ("false positives"), which may run as high as 67% to 75%. Example: SpamCop. I was wrongly reported to SpamCop last week by a subscriber who made a mistake. I corresponded with him. But there was no way for him to correct his error.
4. Bonded senders. These organizations certify an e-mail sender -- for a fee -- as a "good guy" who conforms to permission marketing standards. Headers and whitelists containing certified IP sending addresses identify members. Examples: Habeas (which I use constantly) and IronPort Bonded Sender.
5. Address Recognition. The recipient puts the sender's e-mail address in an address book or a local whitelist that allows e-mails to stay out of the bulk mail folder. Examples: AOL and HotMail.
6. Spam Trap. Filter companies plant e-mail addresses on websites with the hopes that they will be sucked up by spam robots. When any of these e-mail addresses is used, the e-mails and senders are labeled (correctly) as spam. Example: Brightmail.
7. Probability. A rule-based artificial intelligence program learns over time what a particular recipient considers spam and then filters for that. Example: AOL 9.0
8. Challenge-Response. Senders must respond to an e-mail by typing in a code or word to prove that a real person has sent the e-mail. If senders don't monitor their reply address e-mail box, they'll miss responding to these. Example: SpamArrest and ChoiceMail One.
9. Volume Blocking. If you send a mailing that contains a large number of obsolete or bouncing e-mail addresses to a particular ISP, after a certain threshold, all the rest of your e-mail messages to recipients  that ISP's recipients will be junked without trying to deliver them. Bummer! Keep your lists clean!

In chapter 3, Jill identifies the top e-mail filters. Brightmail, which feeds huge ISPs such as Hotmail, MSN, AT&T and Earthlink, has the lowest percentage of false positives in the industry. Of course, AOL and Yahoo! Email are notorious for rejecting legitimate opt-in e-mails, though hopefully they're getting better. Hundreds of ISPs and corporations outsource to Postini. SpamAssassin may affect 100 million e-mail boxes. It uses a point system based partly on words and phrases commonly used in spam messages. McAfee SpamKiller is used by many small businesses and individuals, but may have high false positives. Ask recipients to put you on their safe list.

In chapter 4, Jill makes several recommendations to improve deliverability, including:

1. Use a double-opt-in procedure to get subscriptions. It cuts spam complaints from subscribers and helps develop a more trusting relationship with ISPs, blacklist companies, and e-mail list hosts.
2. Provide a one-click unsubscribe process in every message. Make sure the recipient doesn't need a password to unsubscribe. 
3. Send regular e-mails within 90 days of receiving permission in order to keep subscribers from forgetting they subscribed and assuming you are a spammer.
4. Find the best e-mail service you can afford to send your e-mails. Consider (a) proven ability to get mail through, (b) vendor relationships with major ISPs, (c) willingness to give you a unique IP address that no other mailer can use, (d) policies that allow opt-out lists as clients, (e) ability to segment your list based on open rates, bounce types, source of names, and permission level, and (f) availability of a "do not send" or suppression list.
5. Try to get your subscribers to put you in their whitelist or address book. Jill tells you specifically how -- and how not -- to do this.
6. Carefully format HTML e-mails to avoid errors that will brand you as a spammer.
7. See that the FROM e-mail address is hosted on the server sending the e-mail so you aren't suspected of forging headers. (This is a complex, technical subject that is well-explained in the e-book.)
8. Avoid hyped up marketing words or phrases commonly used by spammers. (See my list of words and phrases at http://www.wilsonweb.com/wmt8/spamfilter_phrases.htm )
9. Avoid using all caps and obnoxious punctuation (such as several exclamation marks). There are lots of other things to avoid. See Jill's e-book for details.
10. Regularly check major spam databases. More about this in my article "Whitelisting and Blacklisting," Doctor Ebiz, 9/10/2003 (http://www.doctorebiz.com/08/030910a.htm). Jill's e-book gives two pages of detailed procedures to answer the question, "What to do if you're blacklisted?" -- well worth the price of the book.
11. Set up e-mail addresses with the major ISPs and seed them in your lists to check on deliverability.
12. Watch your reply box for challenge-response spam blocks.
13. Use a certified or bonded sender program, such as Habeas, IronPort, or Postiva.

 There's lot's more in this e-book -- a look at that's ahead for e-mail deliverability, instructions on "How to Clean Your List," and "7 Ways to Stop Names from Going Bad." All in all, if you're serious about increasing the deliverability and responsiveness of your e-mail list, The Permission Emailer's Guide to Avoiding Filters is important reading. Strongly recommended.