What sender reputation is#
Sender reputation is the score mailbox providers assign to a sending domain and IP based on complaint rates, bounce rates, engagement, spam-trap hits, and authentication history. It determines whether mail is delivered, filtered, or rejected.
Why it matters#
Reputation is the dominant factor in inbox placement. Content matters far less than the trust a provider has in your domain.
What Postmark handles#
Most platforms, including Postmark, generate the records or settings you need under a domain authentication or sending settings page, and expose bounce and complaint data in reports. Confirm the exact location in Postmark's current documentation.
What you still own#
- Register in Google Postmaster Tools and Microsoft SNDS to see your domain and IP reputation directly.
- Keep spam complaints below 0.1% (Gmail's threshold is 0.3% for enforcement) and hard bounces below 2%.
- Segment by engagement and stop sending to contacts inactive for 90+ days.
- Authenticate with SPF, DKIM, and DMARC so reputation accrues to your domain rather than a shared IP.
- Ramp volume gradually after any pause longer than two weeks.
Common mistakes#
- Buying or scraping lists, which seed spam traps into your database.
- Blasting an entire list after months of silence.
- Ignoring Postmaster Tools until placement has already collapsed.
Frequently asked questions#
Domain reputation vs IP reputation: which matters more?
Domain reputation now dominates at Gmail and Yahoo. IP still matters for Microsoft and for dedicated-IP senders.
How long does it take to repair a bad reputation?
Four to eight weeks of clean, low-volume sending to engaged recipients is typical.
Does Postmark set up sender reputation automatically?
Postmark provides the values and some checks, but publishing DNS, aligning domains, and monitoring results remain your responsibility.