It is vital that you pay attention to the percentage of unsubscribers and spam.
Constantly review emails sent before and have had low performance on these two points: unsubscribers and spam. Consider what could have caused a low percentage of recipients. To do this I recommend you do the following:
• Make time to discover what topics are of interest to its subscribers.
• Send a survey of various topics and interests and give them the opportunity to write their topics of interest. You may also ask them the reasons why they would unsubscribe to your list, so you can analyze more thoroughly why the other readers did.
Remember that if your percentage of spam is high, your emails can start being blocked. So make sure your lists are all opt-in, follow the basic standards when creating your newsletters and remember not to buy databases.