First lets explain what is an abuse rate. Abuse rate is the number that says how many recipients (out of the total amount) have, for any reason, reported that your email was abusive (or not wanted).
Unfortunately, there is a lot of instances in which a regular contact will, in an effort to stop getting emails that they subscribed to, will hit “report spam” button instead of using an unsubscribe link in your email message to properly remove themselves from your list, without affecting your deliverability rate. Having a high abuse rate (even one percent of the list reporting it is a dangerously high number) will cause your future emails not to be delivered, and your sending domain to be marked as a spammer / added to blacklists.
There are multiple ways someone can report an abuse on a clean list, but clicking the “mark as spam” or “report spam” is considered one of the most common ways. Besides that, the abuses can be logged via feedback loops, or if any recipient directly contacts the email sender (usually by emailing abuse@ email address on that server). Of course, by using a paid/rented list, you can count on having a high abuse rate, as those contacts did not subscribe to receive your emails in the first place. They are most likely to report a lot of abuse complaints.
Here is a couple of advices on how to avoid having a high abuse rate:
- Send emails only to double opted-in lists, that were not purchased or obtained for any other reason than to have you email your contacts.
- Refer to your contacts by name. Also, mentioning how and when did they subscribe to receive your emails is always good, as it serves as a reminder to your recipients in case they forgot why they are receiving your emails.
- Show an unsubscribe link in a prominent position, somewhere close to the top of the email. You would need this to try to push your contacts toward unsubscribing from your list instead of marking your message as a spam. Many email users will simply hit “mark as spam” if they do not want to receive your emails anymore (which is pretty bad, as they are marking you as a spammer instead of simply unsubscribing). Since you can not affect recipient’s behavior, you can fight that by adding an unsubscribe link somewhere where they can see it.
- Add a note on top of the message indicating how they were added to your list, there is always a chance that your contacts may forget that they subscribed to your list. If this happens, they may just simply mark you as spam. A note on top of your email will help remind your contacts how they got into your list and why they are getting your emails. This will help in reducing your spam reports.
- Email message should not consist of image only, or less than a few paragraphs — specially if it includes a link. By having a short email that only references a link will greatly increase your abuse rate. (In most cases, the email will not even show the image at first, so if your contacts do not know what it is, the chance is big that the email will end up marked as a spam.)
- Sending non-personalized emails to the same server (at a fast rate). The destination server might consider this a DDoS attack, and might drop your emails, or even worse add you to the spam filter blacklist.
- Do not send text only emails, as they look like a spam in most cases. Also, try to use a header similar to your site header, in attempt to help your recipients recognize your brand faster.
- If sending a link, provide description/explanation for the link (an excerpt will do). Sending just a “please check out this link” is not enough — most emails like those are marked as spam and their senders will receive abuse reports.