Email verification for recruiters working sourced lists
Recruiters work two kinds of candidate address, and they fail in different ways. A personal address a candidate gave you two years ago usually still works. A work address from a sourcing tool or a data provider is built from a pattern, and the person behind it may have moved on.
ZapBounce checks both before the first message goes out. You upload the list, our own SMTP check asks each mail server about the mailbox and closes before DATA, and every row comes back valid, invalid, catch-all or unknown. Unknowns are never billed.
Lists from sourcing tools and data providers are welcome. You confirm a lawful basis to process the addresses, as with any list, and the check itself never contacts the candidate.
Why sourced candidate lists bounce
Sourcing tools build work addresses by applying a company's observed pattern, such as first.last, to a name from a profile. The pattern is usually right. The person is sometimes gone, and the mailbox closed when they left answers 550 to your outreach.
Corporate domains are also where catch-all servers cluster. In one 10,000-address B2B benchmark, about 28% of addresses sat on catch-all domains, and a 250 from one of those servers confirms nothing about the mailbox.
Every one of those bounces lands on your sending domain, the same one your client updates go out from. That's the real cost of a dirty sourcing list, and it shows up weeks later as weaker delivery everywhere.
Candidates change jobs faster than anyone else in your database. A list you verified in spring is a snapshot by autumn, so the check belongs right before each campaign rather than once a year.
How the work gets done
The order that matters for recruiters, rather than a generic checklist.
Verify sourced addresses before the first touch
Run anything a sourcing tool or data provider generated, rather than a candidate typed, through a bulk upload. That's the segment that produces the bounces, and 1,000 checks cost $5.
Send catch-all rows as their own segment
Large employers often run accept-all mail servers. Treat those addresses as unconfirmed, start with a small batch per company, and keep the ones that don't bounce.
Keep the personal address as the fallback
A candidate's own address survives a job change and the work address does not. Verify both and you keep a route when someone moves.
Check the address you have, not every variation
Verify the one address your sourcing tool returned. Running every first.last and f.last variation to find a match is address discovery, which the acceptable use terms rule out.
Re-verify the pipeline every quarter
In a database of people whose job is changing jobs, a quarterly check matches the pace of decay. Credits never expire, so a pack bought for one search covers the next.
The hard cases in recruiters, and how they come back
What it costs
A 10,000-candidate pipeline costs $25 to check, and 50,000 costs $89. Credits never expire, which suits a desk that hires in waves, and a monthly plan costs 15% less than the same credits pay-as-you-go, with unused credits rolling over while the plan is active.
Every tier works the same way. Unknown results and duplicates are never billed, and credits do not expire.
Questions we get asked
Can I verify a candidate list from a sourcing tool or data provider?
Yes. You confirm you have a lawful basis to process every address, including lists bought from a data provider, and ZapBounce checks them like any other list. Verification never contacts the candidate, and it never counts as consent to email anyone.
Why do so many corporate candidate addresses come back catch-all?
Accept-all routing is a common setting on company mail servers, so every address at that domain returns 250. In one 10,000-address B2B benchmark about 28% of addresses sat on such domains. The honest label for those rows is catch-all.
Is verification worth it for a small sourcing list?
Yes, because a small list costs a few dollars at most. The free tier covers 100 checks a month with no card, and a 1,000-check pack costs $5.
Does verifying a candidate's address send them anything?
No. The SMTP connection closes before DATA, so nothing reaches the candidate's inbox.
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.