Sender Reputation

Sender reputation is a score assigned by Internet Service Providers (ISPs) to email senders based on their sending history, recipient engagement, and adherence to email best practices. This reputation directly impacts email deliverability – senders with good reputations see their emails delivered to inboxes, while those with poor reputations have emails filtered to spam folders or blocked entirely. For cold email marketers, maintaining strong sender reputation is essential for campaign success and long-term email deliverability.

Sender reputation is influenced by multiple factors that ISPs monitor continuously. Bounce rates should remain below 2% – high bounce rates indicate poor list quality and damage reputation. Spam complaint rates must stay under 0.1%, as recipients marking emails as spam strongly signals unwanted content. Engagement metrics like open rates, click-through rates, and time spent reading emails also factor into reputation scores. ISPs also consider sending volume consistency – sudden spikes in email volume can trigger suspicion, while gradual increases are viewed more favorably.

Building and maintaining good sender reputation requires consistent adherence to email best practices over time. Implement proper authentication protocols (SPF, DKIM, DMARC) to verify your identity. Maintain clean email lists by regularly removing bounced addresses and respecting unsubscribe requests immediately. Focus on sending relevant, valuable content that recipients want to receive. Gradually warm up new email accounts and domains before launching full campaigns. Monitor your reputation using tools like Sender Score, Google Postmaster Tools, or Microsoft SNDS. If your reputation becomes damaged, recovery requires addressing the root causes and demonstrating improved sending practices over several weeks or months. Remember that sender reputation is easier to maintain than to repair, making prevention the best strategy.