Delivering email newsletters and sales messages to opt-in subscribers and customers is getting more exasperatingand more expensiveby the day. Delivery rates for email have gone through the virtual floor. According to MarketingSherpa, one out of every six people who asked to be on your mailing list won't receive your email newsletter or marketing message because a spam filter blocks it by mistake.

Why youre just not getting through to them
As you probably know, the challenge you are facing is primarily spam filters, electronic and human. And no wonder. Consider these sobering numbers:

• 10 out of 12 messages reviewed are considered spam (Postini.com)

• average users receive 42 unwanted sales pitches a day (Jupiter Research)

• 70% of all email messages will be spam by 2007 (Radicati Group)

Your emails fail to reach your subscribers for three basic reasons. Either the email is blocked by the subscribers ISP or enterprise firewall (in which case it never gets delivered), the email is blocked by the subscribers spam filter (in which case it gets delivered but is never seen) or the email is deleted by an irritable subscriber with an overzealous delete-key-finger who does not recognize your From: address or mistakes your email subject line for something unwelcome.

But take heart. There are some tactics you can employ today to increase your email deliverability scores and reach your newsletter subscribers and customers with the email messages they have asked you to wing their way.

1. Hire someone to monitor your mail
Your most expensive option is to retain the services of a third-party vendor to monitor your email deliverability. For a fee, ReturnPath.net, PiperSoftware.com, Deliverability.com, DeliveryMonitor.com and other companies will seed your mailing list seeded with hundreds of email addresses from a variety of domains. When your email arrives, these firms record the time, count the number of emails that escaped the spam filters, and generate a report that shows deliverability scores for each ISP. These reports help you notice which ISPs are blocking your messages or only allowing a few to get through before blocking the rest. You can take the steps needed to improve deliverability.

2. Test your email messages for spam before sending
The above companies and a host of smaller software firms let you run your email message by a spam filter before sending. They search for free, buy now and other words that trigger spam filters. That way, you can see if your message is likely to be flagged as spam somewhere enroute, and tweak where needed to improve your score before hitting Send. Try the free service at www.ezinecheck.com.

3. Make sure your ISP is not on a blacklist
Spammers may have abused the servers of the autoresponder or listserver service that you use. As a result, the major ISPs may have blacklisted or blocked emails from these servers. To discover if you are blacklisted, find the IP address of the email server and do a spam database lookup at www. DNSstuff.com or www.OpenRBL.org.

4. Slow down your email send rate
Some ISPs set a threshold for how many emails you can send during one session. If you exceed this threshold, their software flags you as a spammer and blocks the remainder of your messages. One way around this wall is to send your messages in small bursts, say 200 at a time, with a pause of a few minutes between bursts. The other solution is to host your list on a reputable listserver. The more popular ones include Constant Contact, AWeber, Topica, and GotMarketing Campaigner.

5. Send your email when its most likely to get read
If you send your message to businesses on a Friday afternoon, chances are that your recipients wont check their email until Monday morning. Your message will be buried way down the list with a ton of spam ahead of it (assuming the recipients inbox is sorted by date). The most recent messages will get the attention, and your message will likely get overlooked or deleted in the rush to start work. The open rate for email is strongest within the first two days of delivery. Then it drops off a cliff.

6. Mail on the best days
Online marketers have discovered over the years that B to B emails are read most often when they arrive on a Tuesday, Wednesday or Thursday, around noon. Mondays are too busy. And Fridays are too close to the golf course.

7. Use the right email service
Choose a reputable service provider who is respected by the major ISPs. They will work on your behalf to keep you off blacklists and deliver your messages on time.

8. Help subscribers change addresses
In every email message, tell your subscribers where they need to go to change their address or modify their subscription. Youll reduce the number of bouncebacks you receive each mailing.

9. Use creative copy tactics to circumvent spam filters
Spam filters block your e-newsletters and marketing messages in a number of ways, and one of them is looking for words that are found in most spam. These include perfectly legitimate words and phrases, such as free, opportunity, multi-level marketing [OK, that one is debatable], compare rates and free installation. Most of these words you can get around by employing a thesaurus. Instead of saying free, say complimentary, or no charge. You can also disguise the word in some way (free becomes free~, or fr*ee), although you must tell your subscribers what you are doing beforehand.

10. Get your subscribers to whitelist you
When your subscribers opt-in to your list, immediately tell them to add your sending email address to their whitelist or allowed senders list so your messages are never blocked by the subscribers spam filters.

11. Use a distinctive, predictable subject line
Include a phrase in every subject line that shows at a glance who you are and what your message is about. Subscribers get used to recognizing each message from you. For example, one popular e-newsletter includes the phrase DM News-iMarketing News Daily in every email subject line.

12. Welcome new subscribers immediately
As soon as someone signs up for your e-newsletter or opts-in to your list, send them a welcome email. Immediately establish a connection between their opt-in action and your email that confirms their membership.

13. Make your email welcome message look like your sign-up form
Help new subscribers to recognize you in their inboxes by branding your online sign-up page and your welcome email with the same colors, images and typography.

14. Send from the same domain that signs them up
The domain in your welcome message and subsequent messages should match the URL of the webpage that subscribers used to opt-in to your list, otherwise they may not recognize you as the sender and delete your message by mistake.

15. Use the same From: address
Keep your From: address constant. This helps subscribers who have added your email address to their whitelist or allowed senders list.