Sender Score

Sender score is a reputation metric, typically rated on a scale of 0 to 100, that evaluates how trustworthy your email sending infrastructure is in the eyes of mailbox providers. A higher score means your emails are more likely to reach the inbox, while a low score increases the chances of your messages being filtered to spam or blocked outright. For B2B sales teams, monitoring and maintaining a healthy sender score is critical to outreach success.

The score is influenced by several behavioral signals: bounce rates, spam complaint rates, the volume and consistency of emails sent, engagement from recipients, and whether your emails appear on any blocklists. Each of these factors feeds into the algorithms that mailbox providers use to evaluate incoming mail. A single campaign sent to a poorly maintained list can tank your sender score and impact deliverability for weeks.

Maintaining a strong sender score requires disciplined list management and sending practices. Warm up new sending domains gradually, and avoid sudden spikes in email volume that can trigger suspicion from email providers.

Key Points

• Rated on a scale of 0 to 100, with higher scores indicating better trustworthiness
• Influenced by bounce rates, spam complaints, engagement, and blocklist status
• Directly impacts whether your emails reach the inbox or get filtered

How It Works

Email reputation services aggregate data from mailbox providers, ISPs, and blocklist operators to calculate a sender score for each IP address or domain. When you send an email, the receiving server checks this score as part of its filtering decision. Scores above 80 generally indicate good deliverability, while scores below 50 often result in heavy spam filtering.

Best Practices

• Regularly check your sender score using free online tools
• Maintain consistent sending volumes and avoid abrupt spikes

Free Tools

• Email Checker
• Email Reputation Checker
• Email Verifier