You send regular email newsletters to your audience. Most likely you're using tools like ConvertKit or Mailchimp to manage your Email Lists and schedule the send-out.
In your email list, you accumulate email addresses that cannot be delivered. So-called bounces. This can happen because of typos or because the email address became invalid in the meantime.
The problem with bounces: Frequently sending emails to non-existing email addresses have a negative effect on your reputation as a sender. ESPs may classify your emails as SPAM. This hurts the success rate of your email campaign.
Focus on maintaining a great email reputation score to optimize your email marketing efforts.
Having a high number of spam complaints may have a negative impact on your mailbox delivery. With an increasing number of spam or junk complaints, your domain reputation goes down. Having a low domain reputation means that your emails are more likely to go straight to the spam folder or even get blocked by the ESP (like Gmail).
Keeping the number of spam complaints low is easy: Just don't send spam! To be more precise, use double-opt for email subscribers. Only send relevant content to your audience and keep your email lists clean by removing inactive subscribers from your email lists from time to time.
Trying to send emails to unknown mailboxes (hard bounces) is another sign for ESPs, that you are a mass email sender with a low-quality email list. Most likely an indication, that someone is sending unsolicited emails to the recipients.
This is why it is important to remove hard bounces from your email lists. Use an email validation tool to detect invalid and risky email addresses in your email lists.
Having a high number of unsubscriptions is a negative sign and might decrease your sender reputation. It's also a good sign that you're sending emails your recipients don't want to read. This might be related to the content of the email, the frequency or just that the recipient didn't ask for it (signed up).
Know your audience. Make a promise during your newsletter signup and deliver what you promised. Finding the perfect frequency varies on the type of content you're sending.
In general, it is good advice that you should add an unsubscribe option to your marketing emails. You risk a much higher spam complaint rate if you don't add an obvious unsubscribe option.
Regularly remove email bounces from your email lists when they happen is an effective approach to keeping your email list clean.
The most effective way is to use services like CampaignKit to keep your email lists clean. Identify invalid and risky emails in your email lists before sending emails to them. You can connect it directly to your email provider or upload your email lists as CSV or Excel.