5 Common Mistakes That Are Destroying Your Sender Reputation

Your sender reputation is one of the most critical factors in email marketing success. If it's poor, your emails won't even make it to the inbox. Are you accidentally sabotaging your own efforts? Here are five common mistakes to avoid.

1. Sending to Unverified Email Lists

This is the cardinal sin of email marketing. Purchasing lists or failing to validate new sign-ups is the fastest way to ruin your reputation. These lists are often filled with invalid addresses, spam traps, and people who never opted in, leading to high bounce rates and spam complaints.

Fix: Never buy a list. Use a double opt-in process for new subscribers and validate your entire list regularly with a service like Cleanmails.

2. Ignoring Engagement Metrics

ISPs track how users interact with your emails. If you continuously send to unengaged contacts (people who never open or click), ISPs see this as a negative signal that your content is not wanted.

Fix: Implement a sunset policy. Regularly prune your list of contacts who haven't engaged in the last 3-6 months. You can try a re-engagement campaign first, but remove them if they remain inactive.

3. Making it Hard to Unsubscribe

Hiding the unsubscribe link in tiny font at the bottom of your email is a terrible practice. If users can't easily find it, their next step is to mark your email as spam, which is far more damaging to your reputation.

Fix: Make your unsubscribe link clear, conspicuous, and easy to use in every email. The process should be a single click, with no need to log in.

4. Poor Email Authentication

Failing to set up SPF, DKIM, and DMARC is like sending mail without a return address. It makes you look suspicious to ISPs and leaves your domain vulnerable to being spoofed by phishers.

Fix: Authenticate your sending domain properly. These DNS records are essential for proving your identity and protecting your brand's reputation.

5. Sudden Spikes in Sending Volume

Suddenly sending a massive number of emails from a new or previously inactive IP address or domain looks like classic spammer behavior to ISPs. They will likely throttle or block your emails as a precaution.

Fix: Warm up your domain/IP by gradually increasing your sending volume over several days or weeks. This builds trust with ISPs and shows them you're a legitimate sender.