Verification normally asks the mail server "does this address exist?" A catch-all server says yes to everything. That is why some addresses show as "catch-all" or "accept all" instead of verified.
Buzzlist shows the status on work emails where the data carries it, on Growth and Scale, so you can see catch-all addresses before you send and decide whether to include them.
A practical rule: send to verified addresses first. Mix in catch-alls in small numbers and watch the bounce rate. Buzzlist pauses a mailbox at a 5 percent bounce rate over 7 days once it has sent 20 or more.
