Don’t buy email lists. Ever. The people on these lists are likely to mark your unsolicited emails as spam, and there’s a good chance that a spamtrap is included in the list. Sending email to a spamtrap will usually land you on a blacklist.
Don’t repeatedly send the same or similar content. Every email you send should consist of unique content. Not only will this help keep you stay off of blacklists, but it will also keep your subscribers engaged.
Don’t string readers along with vague content. Include a clearly written subject line and call to action.
Don’t send attachments, it’s a sure way to get blocked. (Sending attachments may get your email blocked, but not blacklisted. The effect on deliverability may be the same, but the remedy is to simply not send attachments rather than working to get removed from a list).
Don’t use punctuation (such as exclamation marks) or words that are often used by spammers. These include free, win, and opportunity.
Don’t blind carbon copy (BCC) your list.
Don’t use too many images. Strive for a healthy balance of images and text to avoid triggering spam filters.
Don’t use all caps in your subject line – or any other part of your email. Instead, use bold, italics and underline to show emphasis.