Protecting Your Email Sender Reputation at Scale
A practical guide to monitoring bounce rates, managing domain health, and maintaining deliverability across multiple sending accounts.
Understanding Sender Reputation
Your email sender reputation is the single most important factor determining whether your messages reach the inbox. At scale, managing this becomes exponentially more complex.
What Affects Reputation
Several factors contribute to your sender score:
- Bounce Rate: Hard bounces signal you're sending to invalid addresses
- Spam Complaints: Recipients marking your emails as spam
- Engagement: Open rates, replies, and click-through rates
- Sending Volume: Sudden spikes can trigger filters
- Domain Age: Newer domains require careful warm-up
Monitoring at Scale
When running campaigns across dozens of domains and sending accounts, manual monitoring becomes impossible. You need automated systems that:
Track Bounce Codes
Not all bounces are equal. Understanding bounce codes helps you diagnose issues:
- 550 5.1.1: Invalid recipient
- 550 5.7.1: Spam filter rejection
- 421 4.7.0: Rate limiting
Alert on Anomalies
Set up alerts for:
- Bounce rates exceeding 2%
- Sudden drops in open rates
- Spam complaint spikes
Automate Rotation
When a domain shows signs of degradation, automatically rotate to healthy senders while the affected domain recovers.
Proactive Health Management
Don't wait for problems. Build habits that maintain sender health:
The Bottom Line
Sender reputation management isn't glamorous, but it's the foundation of successful outreach. Invest in the infrastructure to monitor and maintain it at scale.