Here are a few tips to make sure that doesn't happen to you.
Only email people who have given you their permission
Surprisingly, many email marketers still send to purchased lists which is a sure fire way to get reported as spam, which can also hurt your future deliverability. Contacts from a purchased list have never heard of your company, and most of them will be confused and annoyed that they are suddenly receiving updates about products and services they’re not interested in or signed up for.
Avoid sending only promotional emails
Unless someone indicates they are ready to buy (maybe they signed up for a trial or asked to be contacted by a sales rep), it’s not a good idea to start marketing to your new leads as if they are ready to buy. By only sending emails like “start your free trial today” and “48 hour sale starts now!” you will turn most people off and give them a good reason to unsubscribe.
Ensure all your links work correctly
There’s nothing more frustrating for you or your subscribers than when a link is broken. Think of all the time and effort you put into copy writing, getting your formatting just right, segmenting your list and building your landing page. If your call-to-action link is useless, the email and landing page are useless and your subscribers aren't going to hunt the information out for themselves.
Don’t use deceptive subject lines
I know it’s difficult to get people to open your emails but using deceptive subject lines to encourage email opens will only lead to angry unsubscribes once the recipient realises you mislead them.
Make it easy to unsubscribe
The key to ensuring customer satisfaction is to make the unsubscribe process easy. The link should be visible, underlined and a one click unsubscribe process.
Don’t forget mobile users
Almost 45% of all emails are opened on a mobile device. If you fail to make your emails mobile responsive you’re just asking for your mobile users to unsubscribe from your email list. Don’t expect your subscribers to zoom, pinch and scroll all over their smartphones or tablet in order to read your email – they won’t.