Wait for the verification code or confirmation link email on a trial inbox: block (up to ttl_seconds, max 60) for the one confirmation email on a trial inbox created by create_trial_inbox. Pass the exact inbox_address that call returned. The inbox does NOT self-delete or become unusable after a match: it keeps receiving mail and can still be claimed afterward (call claim_trial_inbox any time before it expires) if the human wants to keep using the same address. Call this AFTER you have actually used the address somewhere (signed up, requested a code) -- calling it before that will just expire, since there is nothing to wait for yet. 60 seconds is a hard per-call ceiling, not the inbox's total lifetime: a sender that takes longer than that is not a failure, just call this again with the same inbox_address to keep waiting (the inbox stays valid for its full ~2-week expiry, and you can call this again later too, e.g. to catch a second, later email on the same address). Only treat expired as final once you've retried a few times.