Shared sending IP got listed on Barracuda RBL
Your SMTP provider's shared IP pool is listed on Barracuda, affecting all customers on that IP — including you.
You didn't do anything wrong, but Barracuda-protected receivers are rejecting your mail anyway. This is one of the biggest hidden risks of using free or cheap shared-IP email services.
What causes it
- A spammy customer on the same IP got listed and the IP as a whole was blocked.
- The provider rotated your IP without warning into a less-reputable pool.
- The provider's IP pool got listed en masse due to volume abuse by others.
How to fix it
Step 1: Escalate to your provider
Open a support ticket with your email provider. Reputable providers (Postmark, SendGrid, Mailgun) actively monitor their IP reputation and will delist on request — or move you to a cleaner IP.
Step 2: Consider dedicated IP
If this keeps happening, upgrade to a dedicated IP. You bear the full cost of maintaining its reputation, but you also control it. Most providers charge $30-80/mo for a dedicated IP.
Step 3: Multi-provider failover
For high-stakes sending, send through two providers and automatically failover if one is listed. Services like SparkPost Signals or custom logic in your app can handle this.
Fixed it? Run a fresh test to confirm.
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