Definition

Sender reputation is the score inbox providers keep on your sending domain and address, based on how your past emails were received. It is the main input into whether your next email reaches the inbox.

The score moves with behavior. Opens, replies and clicks push it up. Spam complaints, bounces to dead addresses and messages nobody opens push it down. Technical setup matters too: the records that prove your domain is allowed to send email. Sender reputation is not published in one public place, and it is not fixed; a few weeks of good sending can repair it, and a few bad sends can damage it.

A B2B example: a software company starts sending from a brand new domain and immediately blasts thousands of cold addresses. The domain's reputation starts low and sinks further, so even its onboarding emails to paying customers begin getting filtered.

Why it matters for B2B email

In B2B, your most important emails go to a small number of valuable people: trial users, open deals, customers up for renewal. A damaged sender reputation puts all of those at risk at once. Protecting it is cheaper than repairing it, and it mostly comes down to sending wanted email to people who asked for it.

Related terms

Deliverability Deliverability is whether your emails actually land in the inbox, rather than in spam or nowhere at all.
List hygiene List hygiene is the ongoing work of keeping your email list accurate and made of people who want to hear from you.
Double opt-in Double opt-in means a new subscriber has to confirm their email address before they are added to your list.

Part of the B2B email marketing glossary. Last updated 2026-10-08.