Like justice, your marketing emails should not only NOT be spam, they should not appear to be spam. If the recipients doubt that your email is legitimate then there is every chance they will tag it as spam giving rise to all sorts of problems. Worse still it might lead to a complaint and so even more problems. Here are some ways to avoid such pitfalls.
Bought in bulk email lists
Everyone will tell you to create your own in-house email list and there is little doubt that this is good advice. However, if your circumstances demand it then there is nothing, apart from the cost, against buying in a list. If you have to, you have to.
You should not pass the buck by merely asking if the addresses are opt-in. The responsibility to check that everything is above board is down to you. If they are not there is only one person taking the risk. Ensure that all have actively asked to be on the list.
Further, make sure they opted in recently. Someone who subscribed some months ago might well have forgotten. An email from you purporting to be in response to their request might not convince them.
When you get a subscriber send them an email thanking them for doing so but add a note to say that if they received the email in error please go to wherever to unsubscribe. This will limit the chances of being tagged as spam.
Do not wait too long
Even if your product is a once-a-year purchase, do not wait months between emails. A click is difficult to remember. If there are large time gaps between your offers then consider a newsletter or update midway or a couple of weeks before the real marketing email
Emails should not look like spam
Recipients are the most fastidious of spam filters. If yours looks like spam, even just the ‘From’ line, then it might well be tagged as such. Be precise as to the level of familiarity. No “Hi!” as an opening gambit.
Obey the law
Nothing makes people tag an email as spam as when there is no unsubscribe facility.