How to Clean & Verify Your Contact List in FirstSales
Verify addresses before you send — turn on contact cleaning, understand the five checks and the per-contact cost, and re-clean older lists.
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Why a clean list matters
Dead and invalid addresses cause bounces, and bounces wreck sender reputation and inbox placement. Cleaning your list — verifying addresses before you send — is one of the highest-leverage things you can do for deliverability. FirstSales calls this Contact cleaning.
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Turn on automatic cleaning
Go to Settings → Tools and enable Contact cleaning: "Checks email addresses on import so campaigns skip dead ones, reducing your bounce rate and protecting sender reputation." With it on, every contact you import is verified automatically before any campaign can email it.
This is the set-and-forget option — turn it on once and new imports stay clean.
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Understand what it checks
Cleaning runs five checks per address:
- Address format — valid syntax.
- Mail server verification — the domain's MX record exists and the mailbox is reachable.
- Disposable addresses — throwaway inboxes.
- Typo correction — fixes obvious misspellings.
- Role addresses — flags shared inboxes like
info@orsales@.
Re-cleaning also flags catch-all domains, which accept anything and can't be fully verified.
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Know the cost
Cleaning costs 0.2 credits per new contact — it isn't free, but it's cheap insurance against bounces. Importantly, credits are refunded for any contact it can't verify, so you only pay for a definitive result. In your billing consumption history these show as "Contact Cleaning" (and refunds separately).
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Re-clean a list you already imported
Turned cleaning on after importing, or working with an older/bought list? Select the contacts in the Contacts table and click Re-test. The confirmation dialog previews the checks and shows the credit cost for your selection before you confirm. Always re-clean an aging or purchased list before a campaign touches it.
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How results are used
Each contact gets a verification status. Addresses marked dirty are excluded from sends automatically — no manual suppression list needed. If you're sure a flagged contact is valid, Mark valid to override and include them.
Cleaning also de-duplicates on import (by email), so the same person isn't emailed twice from one list.
Pro tips
Hard-won shortcuts that keep warm-up on track.
Cleaning pays for itself in reputation
At 0.2 credits per contact — refunded when it can't verify — cleaning is far cheaper than the deliverability hit a spike of bounces causes. Leave it on.
Always re-clean bought or aged lists
Any list you didn't just import cleanly — purchased, exported, months old — should go through Re-clean first. Email decays; yesterday's valid address bounces today.
Trust the dirty flag
Dirty contacts are auto-excluded so you never build a suppression list by hand. Only Mark valid when you have real reason to believe the address is good.
Catch-all domains are a gray area
Catch-all domains accept any address, so verification can't fully confirm them. Treat catch-all contacts as lower-confidence even when they pass.
Frequently asked questions
Where do I turn on list cleaning?
Settings → Tools, toggle Contact cleaning. Once on, every imported contact is verified automatically before campaigns can send to it.
Is list cleaning free?
No — it costs 0.2 credits per new contact. Credits are refunded for any contact it cannot verify, so you only pay for addresses it can definitively confirm.
What checks does it run?
Address format, mail-server (MX) verification and mailbox reachability, disposable-address detection, typo correction, and role-address flagging. Re-cleaning additionally flags catch-all domains.
Can I clean contacts imported before I enabled it?
Yes. Select them in the Contacts table and click Re-test. The confirmation dialog shows the checks and the credit cost for your selection before you confirm.
What happens to bad addresses?
They're marked dirty and excluded from sends automatically — no manual suppression list. You can Mark valid to override if you're certain an address is good.
Does cleaning remove duplicates?
Yes. On bulk import it de-duplicates by email within your workspace, keeping the first occurrence, so the same contact isn't emailed twice from one list.
How does cleaning improve deliverability?
By keeping bounces low. Campaigns skip verified-bad addresses, so your bounce rate stays under the thresholds that trigger Sender Health warnings — which protects inbox placement for every future send.
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