Verification for the person who owns the send
Email marketers live inside a set of thresholds they did not choose. Under 2% bounces is healthy, over 5% and the ESP treats your list as unmaintained, and the complaint rate has its own separate line in the dashboard.
Verification moves one of those numbers and leaves the rest alone. Knowing which is which saves you from buying a tool to fix a problem it does not touch.
A re-engagement campaign is where a stale list does its damage
The riskiest send in the calendar is the one to people you have not mailed in a year. Every address that died in the meantime bounces at once, the rate spikes past the threshold, and the campaign meant to recover the list is what gets it filtered.
Verification before a re-engagement send is the highest-value single use of this product. You find out what died before the mailbox providers do.
What verification will not touch is the complaint rate. People who mark mail as spam had working addresses, and a cleaner list does not change their mind about wanting the mail.
How the work gets done
The order that matters for email marketers, rather than a generic checklist.
Verify the dormant segment before you mail it
Everyone with no open in twelve months, checked before the re-engagement campaign goes out. This is where the bounce spike would have come from.
Give catch-alls their own send
They cannot be resolved by anyone, so guessing is the only alternative. Send to them as a separate campaign and read the actual bounce rate, which tells you more about that segment than any verifier could.
Keep the unknowns and re-check them
An unknown result means a server would not answer, usually because of greylisting or throttling. Those addresses are often fine. Re-check in two weeks rather than deleting paying customers to improve a percentage.
Move the check to the signup form
Verifying at collection stops the list degrading in the first place, and it catches the gmial.com typo while the person is still on the page to fix it.
What verification will not do here
What it costs
A 50,000-contact list is $89 and a 100,000-contact list is $139. Unknowns and duplicates are not billed, so the invoice tracks the answers you got rather than the row count.
Every tier works the same way. Unknown results and duplicates are never billed, and credits do not expire.
Questions we get asked
How often should I verify?
Before any send to a dormant segment, and quarterly on the active list. B2B data decays faster than B2C because job changes do most of the damage.
Should I delete every catch-all?
No. Plenty of real customers work at companies running accept-all servers. Segment them and let the bounce rate on that segment decide.
Will this fix my inbox placement?
It removes hard bounces, which is one of the larger inputs. Authentication, content and sending consistency are the others, and verification does not touch any of them.
Try it on your own list first
100 free checks a month, no card. Run a sample and read the unresolved count before you decide anything.