Glossary

Email address

The string that identifies a mailbox, in the form local-part@domain.

ValidReach Team · Updated 2026-10-26

In practice

The local part is limited to 64 characters and the whole address to 254. The domain must resolve to a mail server. Addresses can look valid and still not exist.

Example

ana@northwind.example.test: local part “ana”, domain “northwind.example.test”.

Verification and sending

Verification checks syntax first, then the domain and its MX records, then, where the server allows it, the mailbox.