A bounce costs more than the check that would have caught it
Old lists decay. People change jobs, companies close mailboxes, and a list that was good when somebody built it carries more dead addresses the longer it sits. You cannot see that by looking at it. A dead address and a live one are the same string of characters.
Your sending domain finds out the hard way. Mailbox providers judge a sender partly by how much of its mail bounces. Send an unchecked export and the bounces count against the domain, and the damage is not limited to that campaign: your later mail, including replies to live clients, starts landing in spam.
So this play finds nothing. The addresses are already on your list. It gets a verdict on each one and sorts the list into what you can send to, what you should hold, and what you should never send to.
What you get back
Your list with two columns added: the verdict and the group.
Send holds the valid addresses, including catch-all addresses the check was able to confirm. Hold contains catch-all addresses that could not be confirmed, and unknowns. Do not send contains the invalid ones, plus everything the free checks and your suppression list removed, each with its reason.
You also get the counts per group. Nothing is sent and no campaign is touched.
Variations worth knowing
The list is already in a campaign. If the leads sit in Instantly, lemlist or SendKit and the campaign has not started, the agent reads them from there with your own account connected. It reads only. Taking the failed addresses out is yours to do.
Check the sender as well. If you send through SendKit, the agent can also read the health and warm-up state of the mailbox you plan to send from.
Replace the dead ones. Not in this play. Get emails and mobiles for a list you already have finds current addresses for the rows that failed.
Then build the campaign. With a clean send group, build the outreach sequence and keep the hold group out of it.
Where this goes wrong
Treating hold as send. An unconfirmed catch-all address may bounce or may not, and nobody can tell you which. A few in a campaign is a judgement call. A list that is mostly hold is a list to leave alone.
Checking once and sending much later. A verdict describes the mailbox on the day it was checked. If the campaign slips, the check slips with it.
Deliverable is not the same as welcome. A bought list can pass every check and still draw complaints. The check says nothing about whether these people expect to hear from you.
Shared inboxes pass. An info@ address is perfectly deliverable, and nobody you want to reach reads it. That is why they are counted in the free checks and shown to you.
