- 1
Turn on Contact cleaning
The best bounce protection is not sending to dead addresses in the first place. 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."
Once on, every newly imported contact is verified automatically before it can be emailed.
- 2
Know what cleaning checks
Contact cleaning runs five checks on each address:
- Address format — valid syntax.
- Mail server verification — the domain's mail server (MX) exists and the mailbox is reachable.
- Disposable addresses — throwaway inboxes.
- Typo correction — fixes obvious misspellings.
- Role addresses — flags
info@,sales@-type inboxes.
It costs 0.2 credits per new contact, and credits are refunded for any contact it can't verify — you only pay for a real result.
- 3
Re-clean an existing list
Have contacts imported before you turned cleaning on? Select them in the Contacts table and click Re-test. The confirmation dialog shows the same checks — MX existence, mailbox reachability, disposable detection, typo/syntax correction, and catch-all domain flagging — plus the credit cost for the selection before you confirm.
Clean a bought or aging list this way before you point a campaign at it.
- 4
Let suspended contacts drop out automatically
After cleaning, addresses that fail are marked dirty and are excluded from sends automatically — you don't build a suppression list by hand. If you're certain a flagged contact is fine, you can Mark valid to override and include them.
This per-contact status is the suppression mechanism: bounced and unsubscribed contacts are likewise held out of future sends.
- 5
Read bounces in the inbox
When a send does bounce, the conversation shows exactly what happened:
- Soft bounce — temporary; "will retry automatically" (with a retry count).
- Hard bounce — permanent; "Journey ended — recipient bounced," and the contact stops receiving the sequence.
- Blocked — "Blocked by recipient spam filter — check sender reputation."
Each shows the delivery Code and Reason (toggle "Show delivery report"). A blocked bounce is your cue to check warm-up and authentication, not the address.
- 6
Watch your bounce rate in Analytics
Keep an eye on Bounce Rate in the campaign's Engagement strip and Sender Health. Over 5% flags "High bounce rate" health issues and drags down deliverability.
If bounce rate climbs, stop and re-clean the list rather than sending through it — a rising bounce rate compounds into spam-folder placement for every future send.
Pro tips
Hard-won shortcuts that keep warm-up on track.
Prevention beats suppression
Contact cleaning on import stops bounces before they happen. That's cheaper for your reputation than catching bounces after they've already hit inboxes.
You only pay for verifiable contacts
Cleaning is 0.2 credits per contact, but credits are refunded for any address it can't verify. So the effective cost tracks the real, usable part of your list.
Re-clean bought or aged lists first
Any list you didn't just cleanly import — purchased, exported, months old — should go through Re-clean before a campaign touches it. Old lists rot.
A 'Blocked' bounce is a reputation signal
Blocked-by-spam-filter isn't a bad address — it's your sender reputation. Check warm-up score and domain auth rather than deleting the contact.
Frequently asked questions
How do I protect against bounces?
Enable Contact cleaning in Settings → Tools. It verifies every imported address so campaigns skip dead ones, which directly lowers your bounce rate and protects sender reputation.
Is contact cleaning free?
No — it costs 0.2 credits per new contact. However, credits are refunded for any contact it can't verify, so you only pay for addresses it can actually confirm.
What does cleaning check?
Address format, mail-server (MX) verification and mailbox reachability, disposable-address detection, typo correction, and role-address flagging. Re-cleaning also flags catch-all domains.
Can I clean contacts I imported earlier?
Yes. Select them in the Contacts table and click Re-test; the confirmation dialog previews the checks and the credit cost before you confirm.
Is there a suppression list?
Not as a separate page — suppression is handled per contact by status. Contacts marked dirty, bounced, or unsubscribed are automatically excluded from sends. You can Mark valid to override a dirty flag.
What's the difference between a soft and hard bounce?
A soft bounce is temporary and retries automatically; a hard bounce is permanent — the contact's journey ends and they stop receiving the sequence. A blocked result means a spam filter rejected it.
Does FirstSales auto-pause a campaign on high bounces?
There's no dedicated 'auto-pause on bounce' toggle. High bounce rate (over 5%) drives Sender Health warnings so you can act. There is a separate Auto-pause unengaged contacts setting, but that's engagement-based, not bounce-based.
A contact shows 'Blocked' — what should I do?
Blocked means a recipient spam filter rejected the mail — the app tells you to check sender reputation. Look at the mailbox's warm-up score and domain authentication rather than assuming the address is bad.
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