ClearAddress

The whole API is one GET with the email address in the path, exactly how I wish more services worked. curl ca.rda.run/v1/[email protected] and nine JSON fields come back covering syntax, domain, MX, disposable status and a composite isClear verdict. No key, no signup, a ?pretty flag for humans. I ran a stack of addresses from an old newsletter export through it in a shell loop and the disposable flag caught the mailinator aliases hiding in there. They grade a passing address clear rather than valid, and the FAQ explains that distinction without marketing fog. Bookmarkable email validation. Good.

Ran my own address through it before writing this: curl ca.rda.run/v1/[email protected]. No key, no signup, and the answer came back in about 300ms. The checks it claims are the checks it does: it caught a mailinator address as disposable, flagged a dead domain, and rejected a malformed one on syntax. The FAQ won me over as much as the API did. Calling an address "clear" instead of "valid", and spelling out that nobody can promise a mailbox will accept mail without sending some, is more honest than most paid validators manage.

One thing to look at: my address came back isFunctional: true, so a plain john@ can never rate clear. Bare first names seem to sit on the role-account list. john@, mike@ and bob@ all trip it while anna@, jonno@ and john.smith@ pass. Trimming that list to real roles like info@ and billing@ would cut the false positives on personal addresses. A batch endpoint would be my next ask. Good ship.