Given this, don't let all your efforts at creating a snazzy newsletter or e-mail message go to waste by writing a subject line that will land your message in SPAM. It can be avoided if the necessary precautions are taken. Be cautious and attentive to the subject line, avoiding the usual pitfalls and making it engaging to the customer base. Here are a few things to avoid in the subject line – be mindful!

Do not use excessive punctuation – exclamation marks in particular. These will surely catch the attention of a SPAM filter. In general, keep the subject line as you might if you were writing a personal e-mail. This will make the recipient feel more trusting of the source. The moment they see a subject crowded with question marks, exclamation marks, dollar signs, the “at” symbol, or any other punctuation that looks strange, customers will delete, if not mark as SPAM. That is, if the message even gets to their inbox.

There are certain words that will also be flagged as SPAM. “Free” or “Cash” for instance, tend to be more susceptible. But if you are making a give-away offer, don't shy away from using the word “free.” For many companies, these give aways are the key to their campaign – there is no need to completely abandon this idea out of fear that the message will go into the Spam folder. The trick is not to use it at the beginning of your subject line – use it towards the middle or end so that your message will be less suspected by spam detecting software.

To make best use of the space, avoid using unnecessary articles, such as “the” or “a.” A subject line has approximately 50 characters of space, so maximize this space with key words, dates, special prices, and any other important information that needs to be conveyed to get the reader to open the e-mail and explore further.

Content checkers are a safe way to test your subject lines if you are unsure about whether it is SPAM-proof. Use any of the free content checkers you can find online and test the ideas you have brainstormed. Use the ones that are most highly approved by the checker.

Testing is another critical way to determine the viability of your subject line. Do a trial run and send it to various e-mail services to make sure it passes through their SPAM checking systems.

Pay attention to the nuances of a subject line – it is often the most underestimated part of an e-mail campaign, yet it is the most impacting. It can contain the crux of your campaign's message, entice your readers to turn into loyal and returning customers, and possibly pass on the information to their friends.