Status | What it means | Safe to send? |
Valid | The mailbox exists and accepts mail | Yes |
Invalid | The mailbox doesn't exist | No — remove it |
Catch-All | The domain accepts mail for any address, so the specific mailbox can't be confirmed | With caution |
Spam | A spam trap — an address that exists purely to catch senders with poor list hygiene | Never send |
Abuse | Belongs to someone who habitually marks mail as spam | No — remove it |
Do Not Mail | Disposable, role-based, or otherwise flagged as do-not-contact | No — remove it |
Unknown | The server gave no definitive answer | With caution |
⚠️ Spam traps are the one to worry about
A spam trap is the most damaging result you can get. These addresses exist purely to identify senders who don't clean their lists, and hitting one can get your domain blacklisted. Always remove them before sending — no amount of warm-up undoes a blacklisting.
Catch-all domains
Plenty of legitimate companies run catch-all configurations, so a catch-all result isn't a red flag on its own. Send to them, but keep them in a separate segment and watch the bounce rate.
Keeping your bounce rate healthy
Validate every imported list before it goes into a campaign.
Keep your bounce rate under 3%. Above 5%, providers start treating you as a spammer.
Re-validate lists that have been sitting for a few months.