Resources
Short, practical notes on email list hygiene and getting the most out of your verification.
Articles
How to clean an email list before a campaign
A five-step process: export, dedupe, verify, separate role accounts and catch-alls, then send.
Read more →What is a good email bounce rate?
What bounce rate measures, why it affects sender reputation, and when a rising rate means it is time to act.
Read more →How to check if an email address exists without sending to it
The three checks — format, domain and MX records, mailbox — and where catch-all domains limit certainty.
Read more →Quick guides
Why verify your list before you send
Every bounce tells your mail provider your list is stale. Enough of them and legitimate emails start landing in spam, for every recipient, not just the bad addresses. Verifying first protects the sends that matter.
What a bounce actually costs you
It is not just the wasted send. Repeated bounces damage your sender reputation, which lowers inbox placement across your entire list, including the subscribers who were always going to open, click, and buy.
CSV vs Excel: which should you upload?
Either works. CSV is the safer bet for very large exports (smaller file size, fewer formatting quirks). Excel (.xlsx) is fine too, just make sure emails are in a single column, and we'll find it either way.
Reading your results: VALID vs INVALID
VALID means the address is real and reachable. INVALID always comes with a reason: bad format, no mail server, mailbox not found, disposable domain, and so on, so you know whether to remove, fix, or double-check an address.
Role accounts and catch-alls, explained
A role account (info@, support@) belongs to a team, not a person, so it may be valid but rarely converts. A catch-all domain accepts mail to any address whether or not it exists, so "valid" there means less than usual. We flag both so you can judge for yourself.
Getting the most out of a one-time check
Lists decay over time as people change jobs, abandon inboxes, and let domains lapse. A verification is a snapshot of 'right now,' so it is most useful run close to when you plan to send, especially on lists you have not mailed in a while.