What's the best way to handle catch-all emails in my outbound lists?

Catch-all domains are the biggest unsolved problem in email outbound. They can make up 50% of lead lists, so excluding them entirely means losing half your addressable market.

What catch-all actually means: The domain's mail server accepts all emails, so verification tools can't confirm if the specific address exists. The email might work perfectly or bounce hard.

Strategy by risk tolerance:

Conservative (protect sender reputation at all costs):

• Exclude all catch-all emails from cold campaigns
• Only send to explicitly verified deliverable addresses
• You'll have a smaller list but virtually zero bounces
• NeverBounce takes this approach - fewer emails marked safe, but no bounces

Moderate (balanced approach, most teams land here):

• Send to catch-all emails from reputable domains (e.g., enterprise companies)
• Exclude catch-all from small/unknown domains
• Cap catch-all at 20% of any sending batch
• Monitor bounce rates daily and pause if approaching 2%

Aggressive (maximize volume):

• Send to all catch-all with a secondary validation layer
• Use BounceBan or similar second-pass verification - one user caught 62 additional bad addresses on a 483-lead list
• Use MillionVerifier which refunds credits for catch-all results to reduce your verification cost

Practical tip: Send catch-all emails from your warmest, most established domains. New domains should only send to verified-deliverable addresses until reputation is established.