Email Scrubbing: List Hygiene Best Practices and Scrub Schedules
Email lists decay at roughly 22% per year. Regular scrubbing keeps your list healthy, your bounce rate low, and your sender reputation intact.
What Is Email Scrubbing?
Email scrubbing is the process of removing invalid, undeliverable, risky, or disengaged contacts from your mailing list before or between campaigns. It is distinct from real-time verification at point of capture — scrubbing is retrospective, applied to an existing list.
A properly scrubbed list contains only addresses that are syntactically valid, have active mail servers, are not known spam traps, and belong to recipients who have engaged recently enough to remain worth contacting.
What to Remove During a Scrub
Hard bounces
Permanently undeliverable — remove immediately after any campaign.
Repeated soft bounces
Addresses that soft-bounce 3+ consecutive campaigns should be suppressed.
Role accounts
info@, support@, admin@ — low engagement, high complaint risk.
Disposable emails
Temporary domains like mailinator.com or guerrillamail.com.
Spam trap addresses
FareOf flags known trap patterns during verification.
Unsubscribes
Must be suppressed within 2 business days per CAN-SPAM and GDPR.
Catch-all unknowns
Addresses on catch-all domains with no corroborating signals.
Long-term non-openers
No open or click in 12+ months, after a re-engagement attempt fails.
Recommended Scrub Schedule
Cadence by list activity
| Send Frequency | Recommended Scrub Cadence |
|---|---|
| Daily / multiple per week | Monthly + real-time verify at capture |
| Weekly | Every 60 days + after any campaign with >1% bounce |
| Monthly | Every 90 days |
| Quarterly or less | Before every campaign send |
| Re-activating a dormant list | Full scrub before any send — no exceptions |
Step-by-Step Scrub Process
- 1
Export your full list
Download every contact from your ESP with their status, last engagement date, and bounce history.
- 2
Apply hard suppression first
Remove all known hard bounces, unsubscribes, and spam complainants. These are non-negotiable.
- 3
Run bulk verification
Upload the remaining list to FareOf. You receive status codes: valid, invalid, risky, catch-all, disposable.
- 4
Remove invalid and disposable
Delete all addresses returned as invalid or disposable — no exceptions.
- 5
Review risky and catch-all
Suppress if your bounce rate is already above 1%. Otherwise, apply secondary confidence signals.
- 6
Segment by engagement
Separate contacts by last open/click: 0–90 days, 90–180, 180–365, 365+ days.
- 7
Run re-engagement on cold segments
Send a single re-permission email to 180–365 day contacts. Suppress non-responders.
- 8
Suppress 365+ day non-engagers
Remove anyone unresponsive to re-engagement after 12+ months of inactivity.
- 9
Import clean list back to ESP
Upload only verified, engaged contacts. Update suppression lists simultaneously.
List Hygiene Checklist
- Real-time verification at every sign-up form and API entry point
- Hard bounces suppressed automatically after every campaign
- Unsubscribe requests processed within 2 business days
- One-click unsubscribe header present in all bulk emails (RFC 8058)
- Full list scrub completed on schedule per cadence table above
- Re-engagement campaign run before suppressing cold contacts
- Role account filter active in FareOf settings
- Disposable email filter active at point of capture
Scrub your list in minutes
Upload a CSV and get back a clean, verified list with status codes for every address.
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