There can be many reasons why the recipient's host filters may mark your email as SPAM or SPAM-suspected, even if your message is not in fact unsolicited commercial email (UCE). Below you find some information that may be helpful in creating a successful email campaign.
The email's content has the greatest influence on the filter's decision. Here are some things to avoid:
Avoid caps. JUST BECAUSE YOU THINK YOUR MESSAGE WILL RING LOUD AND CLEAR IN ALL CAPS DOESN'T MEAN IT WILL ACTUALLY MAKE IT TO YOUR RECIPIENT. Spam blocker software and email filters are designed to look for capital letters and will immediately flush your message.
Avoid excessive use of exclamation marks. Your message is powerful!!!!!! What could convey that better than a few dozen exclamation marks at the end of your sentences? This is another alarm signal for spam blocker software and email filters. Exclamation cannot prove a point any better than simple text, especially when abundant exclamation marks get your message trashed before it even reaches your intended audience.
Avoid repeating the same words and phrases over and over. In advertising, you are taught to send a subtle message that makes solid and clear points. You can do this without being repetitive. Many people Buy Diet Pills and when they run out they Buy Diet Pills and what could be better than you choosing to Buy Diet Pills... This is another tip off to antispam software and email filters to block your effort at communication.
Additional helpful tips to avoid being blocked:
The recipient's personal identity and context should be clearly stated in the message. If the message appear to be equally applicable to many other potential recipients, it is treated as SPAM-suspected. You can avoid this by addressing the message to a specific recipient (Mr. NAME or Ms. NAME).
Add a couple of words as to where/when the recipient left a request to receive your newsletter/updates/reminders/etc.
Specify a clear and easy way to unsubscribe (preferably a live link or equivalent).
Include your university's contact information along with its postal, geographical address.
Helpful Hint: It is always helpful to send your message to yourself while having your spam blocker software turned on. If your own spam blocker software catches your email, chances are it will also be caught by someone else's. Play around with your message until it goes safely though your spam blocker or filter. When it arrives uncaught in your own inbox, you are ready for your email ad campaign to launch.