Talk to any e-mail marketing professional and they will all tell you deliverability is primary key to success. If your message, no matter how important and/or relevant doesn’t make it to your prospects in-box, it has zero chance to be successful. It is just that stupid simple.

However, once delivered the message has to cut through all the other clutter and noise in person’s in-box to have a chance to be read. But how exactly do you do that? Write an effective subject line, which is the single most important variable related to open rates.

1. Keep It Simple. Don’t try and over engineer or over think your subject line. Take either your offer or single most important message and convey it in under 10 words (five is better) and 50 characters. Also, never use all caps and avoid any unnecessary punctuation.

2. Think relationship, not message. With e-mail marketing you should be trying to build relationships with your readers, not just generate leads or sales. Therefore each message you send should try build and strengthen that relationship and reaffirm why subscribers signed up in the first place. Each message should not be an isolated communication but instead should be somehow related to previous/future e-mails.

3. Be specific, descriptive. Let subscribers know exactly what they can expect to gain if they open your e-mail. If your content is truly relevant to your audience a descriptive subject line will improve your open rates. Example: “Use Google Analytics To Track Landing Pages” is better than “How To Track Leads.”

4. Have someone write the subject line that did not write the copy. This may sound counter intuitive. However, often the copywriter can’t see the “forest for the tree” cause they are too close to the content. Therefore have a few folks read the message and sum up the key points. These use these points as your starting point and then write the subject line with one thought in mind: “why is this important to my audience and how will they benefit”.

5. Test, test and test. Not all people are the same so don’t treat your e-mail audience as if they were. Different people will react to different messages. Segment your list a test different subject lines with each campaign and see which perform the best.

5. Audience segmentation. Just as all people are not the same, neither are all audiences. Prospects will respond to different subject lines than clients, former clients, or partners. Of course it is easier to just write on e-mail and subject line and “blast” it out to everybody, but your results will suffer.

Give these straightforward and simple Subject Line tips a try and watch your open rates increase.