Sender reputation best practices for SaaS companies

Transactional and lifecycle mail share a brand, so one bad campaign can degrade password-reset delivery.

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.

Implementation plan for SaaS companies#

1. Register in Google Postmaster Tools and Microsoft SNDS to see your domain and IP reputation directly.
2. Keep spam complaints below 0.1% (Gmail's threshold is 0.3% for enforcement) and hard bounces below 2%.
3. Segment by engagement and stop sending to contacts inactive for 90+ days.
4. Authenticate with SPF, DKIM, and DMARC so reputation accrues to your domain rather than a shared IP.
5. Ramp volume gradually after any pause longer than two weeks.

Priorities specific to SaaS companies#

Transactional and lifecycle mail share a brand, so one bad campaign can degrade password-reset delivery. Weight your effort toward the steps above that address this constraint first, and measure with metrics that match how SaaS companies generate value from email.

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#