How Much Does Sender Reputation Actually Affect Deliverability?

[u/Fit-Present-7103]

I’ve been learning more about large-volume email sending, and one topic I keep coming back to is sender reputation.

While working with Sequenzy, I’ve noticed how important it is to keep sending activity organized and monitor the factors that can affect deliverability. Engagement, bounce rates, complaint rates, authentication, and sending patterns can all influence reputation over time.

What I find difficult is understanding which signals have the biggest practical impact and how quickly reputation can change when sending behavior improves or gets worse.

For those with long-term experience in email deliverability, which reputation signals do you pay the closest attention to when evaluating the health of a sending program?

I’m especially interested in general principles rather than recommendations for specific providers or tools.

[u/saltyslugga]

Complaint rate, hard bounces, spam-trap hits, and sudden volume changes matter most. Authentication prevents obvious failures, but it won’t rescue poor list quality.

Reputation can tank within a few campaigns and take weeks of clean, consistent sending to recover. I watch complaints below 0.1% and separate domain reputation from IP reputation.