If you’re like many small business email marketers you have a number of opt-in subscribers who are employed or students at a college or university. Indeed, many online marketers who specialize in the youth market may find that this type of email address (.edu) could constitute the majority of their subscription list.

Due to the way the calendar fell this past year many universities and colleges closed on the afternoon of Wednesday December 21 and did not reopen until the morning of Tuesday January 3, leading to a twelve and a half day gap when their internal computer sciences departments, which generally operate the mail servers, were shut down and empty.

Emails of any kind – whether marketing-related or personal – sent to any address on those servers would bounce back, and not in the “soft” way of overfull mailbox or internal internet traffic problem, but as a “hard” non-existent address: The kind that can devastate the legitimate online reputation you’ve worked so hard to build.

Academia is not alone in evacuating during the holidays. Small business email marketers also heed the siren call of warm southern beaches or snowy holidays at Grandma’s house at that time of the year, so they may have set up their email marketing to be issued on autopilot during that late December 2011 to early January 2012 period.

Let’s assume that your e-tailing business regularly sends out your newsletters on Mondays and Thursdays. You would have received a total of four hard bounces on each of your “temporarily closed” .edu customers. Even if those addresses comprise a small percentage of your total overall sends, you might face an unpleasant surprise on your first day back at work: An avalanche of mailer daemon notifications and an urgent missive from your email service provider featuring the words no online marketer ever wants to read: blockage & blacklist.

International educational institutions do not necessarily adhere to the .edu TLD, so just separating those specific addresses from your holiday period sending is not sufficient. Most colleges and universities in Canada, for example, use the national .ca TLD with no .edu in sight. If this is confusing, you’re not alone.

When Microsoft offered their Office Home & Student Ultimate Steal package, where registered students could obtain a discount on a purchase of the software, they placed a boneheaded insistence on a .edu address in blissful ignorance that most Canadian academic institutions don’t use it, thus blocking most of their potential buyers!

Your email subscription list may have to be manually reviewed address by address… an overwhelming task for the email marketer with a list totaling in the millions. It is also questionable whether any manual reviewer will be able to determine that carleton.ca or concordia.ca are actually universities and not commercial Canadian domains!

The same applies to most international universities anywhere: Can you determine at a glance what ensad.fr, lum.it or ras.ru are? Even though there are some national TLDs that indicate an academic institution without the critical .edu, such as ac.uk in the United Kingdom, ac.id in Indonesia and ac.jp in Japan, pulling college and university domains out of a list can turn out to pose a massive migraine to small business email marketers.

It may be well nigh impossible to reverse engineer a completely correct list of your academic institution students and staff, so your best tactic is to rely on your Preference Center. Ensure that you allow your subscriber to check off if their email address belongs to an academic institution, as there may be no reasonably feasible way to determine it otherwise.

If you are not yet incentivizing your subscribers to keep their contact information current and accurate – you should start yesterday, as an effective Preference Center can be the most significant factor in ensuring deliverability and thus your online reputation.

Start preparing now for the next holiday season so that you won’t be caught unaware and have your online rep trashed!