Find out from Habeas' knowledge engineer how to boost email delivery rates by as much as 30 percent.

Did you know that when you launch an email campaign, as much as 25 percent of your messages will not be delivered? That's a lot of emails getting lost or caught in spam filters.

But there are steps you can take to reach more of your audience, and subsequently improve your returns and profits. Be proactive and make improvements now so that you can appreciate the results in 2007.

Effective email campaigns require not only marketing savvy, but strong technical support as well. Having the right technical systems in place can improve your email deliverability, and subsequently your returns and profits.

IT departments can help with email delivery in four areas: DNS and environment setup, sending system configuration, outbound message composition and testing/monitoring.

DNS and environment setup
To ensure a proper environment involves about a dozen factors. First, publish sender authentication records. Next, make sure you have fully configured reverse DNS records for the servers that send email, and check that the domain name you announce actually exists at the IP address from which you send messages. Sender transparency is important. Do not send messages from servers using generic or default Windows host names. Publish valid WHOIS records and avoid using services that cloak your identity.

Then, segment your messages according to email types and sources. Separate your transactional messages from your promotional messages and send them from different IP addresses.

Publish a valid MX record for all domains that send email. Then make sure your inbound systems are scaled to fit the volume of outbound email. In general, inbound servers should be prepared to handle approximately 40 percent of the outbound mail. A feedback loop should also be set up, monitored and updated.

Make sure that rejected messages will be rejected during the SMTP transaction stage, and configure your email server to handle "callback verification." While callback verification is controversial because it can resemble an attempt by a spammer to guess a valid email address, it allows a receiving server to check that the purported sender of the message actually has an account on its supposed host and is capable of receiving bounces and delivery status notifications. Also make sure that messages from the "MAIL FROM email address" can be received.

Any messages that bounce or are sent to rejected addresses should be handled quickly, accurately and reliably. Review the email server logs and remove unknown addressees as quickly as possible. Also, have a process in place for monitoring inbound messages for changes and consider inspecting the outbound email server logs as well.

Sending system configuration
In a nutshell, play nicely. Send email in ways that are acceptable to the receivers. Consider the number of concurrent sessions, the number of messages delivered over a certain period of time, the limits on the number of recipients for a single message and the length of time the connection between the servers is held open.

A server should accept up to 100 messages per connection; stay under that threshold. Watch your email servers and be ready to change parameters when necessary.

Outbound message configuration
While these technical issues are unrelated to the sending environment or infrastructure, they can cause delivery problems. If messages are composed in HTML, make sure the HTML encoding is done properly. When sending attachments, know and follow the specific formatting requirements necessary for delivery.

Also, use a List-Unsubscribe header. It can protect your email reputation with MSN/Hotmail if a recipient uses the "this is spam" button as a convenient way to unsubscribe from a mailing list. If you do not use the header, being marked as spam could hurt your reputation.

Testing and monitoring
Having a test plan is essential. Sending a small test campaign before full distribution is often forgotten, to the detriment of a campaign. Send a test message first, make corrections and then complete the distribution. Also plan to test additions or changes to the infrastructure. The website www.dnsstuff.com provides a number of resources to help test your systems. You can set up your own network of test accounts, or use a commercial service like Habeas' Delivery Monitor and Content Check.

Your IT department can help make significant improvements. When done right, a well-configured system can add as much as 30 percent to your overall email delivery rates. Communication between marketing and IT departments is vital to successful campaigns. Have your IT department involved in the planning and execution of your campaign. Use them as an active information source; they should know what other departments are doing to ensure marketing plans are technically possible. The IT department can help marketers steer clear of any potential hazards before too much work has been done. Ideally, you want to have a liaison who can explain technology in non-technical terms.

Nick Nicholas is Knowledge Engineer at Habeas. Read full bio.