Email & SMTP · 1 min read
Low IP Reputation: Restore Sending Credibility
What's happening
The IP address your email is sent from has a poor reputation, so providers block or reject your mail. IP problems often cause outright blocks rather than spam placement. Messages may mention "IP blocked", "poor IP reputation" or a blocklist such as Spamhaus.
Shared vs. dedicated IPs
- On shared IPs, reputation is managed across many senders. If you see IP reputation bounces, the main thing you can control is your own domain reputation and list quality. Contact support if the problem continues.
- On a dedicated IP, the reputation is yours alone, so your sending habits directly affect it.
Fix it
- Check blocklists for your sending IP and request removal after fixing the cause.
- Pause sends to unengaged or unverified contacts.
- Clean your list with email validation and remove hard bounces and complainers.
- Authenticate your domain with SPF, DKIM and DMARC.
- Warm up again: start with small sends to your most engaged contacts and grow volume gradually.
Prevent it
- Send on a steady schedule rather than in bursts.
- Keep bounces below 2% and complaints below 0.1%.
- Monitor reputation with Google Postmaster Tools.