Email seems like a downright institution, on par with the old Bell Telephone Company, compared with real-time communication options like text messaging and microblogging. But email remains one of the most basic ways of getting your message across.

With email, the hope for a conversion (marketing jargon for getting the user to do something you want them to do) begins with the probability that your email's subject line will entice a wary recipient to click "open". The recipient might ignore your email because the subject line comes across as the work of a spammer, hacker, South African hustler ("Good day, I am the Prime Minister of Botswana and I need your bank account numbers...") or media company that isn't ashamed to exhaust its lists.

Bland subject lines can generate high open rates

Writing straightforward subject lines is one way to get recipients to trust and open your email, according to a subject line comparison by email platform company MailChimp. MailChimp analyzed more than 40 million of its users' emails. The ones with the highest open rates (60-87 percent) included clear, if bland, subject lines like "[Company Name] Sales & Marketing Newsletter" and "Invitation from [Company Name]."

Those with the worst open rates (1 to 14 percent) included flashy or vague messages like "It's still summer in Tahoe!" or simply, "Renewal." These findings indicate that it is important to write subject line messages less as an attempt to grab a recipient's attention and more to provide a clear, concise explanation of what the email will entail. 

A/B testing subjects

A/B testing is useful in determining how recipients respond to your email's subject line. Send one subject line to a sample of your list and an alternate subject line to another sample. Determine the best message by looking at the number of click-throughs or opens for each after about an hour (MailChimp's platform will automatically send the winner to the rest of your list).

Think headlines when it comes to writing effective subject lines—place key information first and keep it searchable. Remember, this is prime real estate, so don't populate it with all-caps marketing fluff that will only catch the attention of the spam filter. Use it to explain to the recipient why the email is relevant to them.

Try this: Practice writing effective subject lines by tweeting. A Twitter message is limited to 140 characters, while a subject line is limited to about 50. See how close you can get to sending effective tweets in around 50 characters. Cut any fat and go for concise and transparent. This will be the direction of email marketing as email recipients continue to grow more tech savvy.