Single-address validation

mails.so checks one email address and returns whether it is deliverable, risky, or invalid. A Beam agent calls this the moment an address enters your system, reads the result, and applies your rule, for example accepting a deliverable address, holding a risky one, or rejecting an invalid one at the point of entry. It writes the outcome onto the record. An address that comes back risky, where accepting or rejecting is a judgment call, is passed to a person rather than decided automatically, so a real customer with an unusual address is not turned away by mistake.

Bulk list cleaning

mails.so validates an entire list at once and returns a status per address. A Beam agent starts a bulk check when a list arrives, reads each result, and sorts addresses into keep, review, and remove by your rules. It writes the cleaned list back and records the counts. It also notes the source of each list so repeat problems are easy to trace. A list with an unusually high invalid rate, which often means a bad source rather than bad addresses, is handed to a person before anything is removed.

Risk and deliverability flags

Beyond valid or invalid, mails.so flags addresses that look risky, disposable, or likely to bounce. A Beam agent reads those flags, applies your policy for each type, and either suppresses the address or tags it for a gentler sending rule. It records why each address was flagged so the choice can be audited. When a domain you depend on starts returning risk flags across many addresses, the agent routes it to a person, since that pattern usually reflects a provider issue rather than a list you should discard.