Should I drop or keep catch-all results before sending?

A catch_all result means the receiving domain accepts mail for every address it is offered, valid or not. Valid Email Checker cannot prove a specific catch-all address is real without sending a test message (which we will not do, since it would be a deliverability risk in itself). The decision to keep or drop comes down to who the audience is and what the cost of a bad bounce looks like for the campaign.

Keep catch-all when...

• You're sending to a warm B2B audience where the recipient gave you their work address in person, at a conference, or through a paid platform. The catch-all is almost certainly a legitimate corporate mailbox, and dropping it removes real recipients.
• The domain is one you trust from past experience. Some Fortune 500 companies and most consulting firms run catch-all SMTP. Sending to verified-employee addresses at those domains is normal.
• The campaign is a transactional or follow-up message to someone who explicitly requested it (order confirmation, demo follow-up). Bounce rate on these is moot since you would be sending anyway.

Drop catch-all when...

• You're running cold outreach to a purchased or scraped list. Catch-all bounce rates can hit 30 to 50% on cold lists because the address might be a guess that no real human reads.
• Sender reputation is already shaky. If your domain is rebuilding deliverability after a previous bounce-rate incident, every percentage point of bounce matters. Drop catch-all for the recovery period.
• You're sending a B2C consumer marketing campaign. Most consumer mail providers (Gmail, Yahoo, Outlook.com) are not catch-all. A catch-all in a B2C list is unusual and probably worth investigating before sending.

The compromise: isolate catch-all in a separate send

A common pattern is to put catch-all addresses in their own segment and send to them on a separate schedule with tight monitoring. If bounce rate on that segment goes over your threshold, suppress automatically. Most ESPs let you trigger suppression rules per-segment, and this keeps the safe segment from inheriting any deliverability damage if the catch-all batch goes badly.

Expected bounce-rate numbers

From the data we see across customers running Valid Email Checker pre-campaign:

For the deep mechanics on how the engine detects catch-all in the first place, read how does VEC detect catch-all domains in real-time and the long-form catch-all emails complete guide.