How to syntax-check a single email address

1. Enter the email

   Drop the address into the "Email" field. The tool trims whitespace and lowercases the result before testing — display variations don't matter.

2. Press Run

   Result returns `valid` (boolean) plus `reason` if false. The matcher uses a pragmatic regex (one `@`, at least one `.` in the domain, no spaces) — strict RFC 5322 quoted-locals and IP-literal hosts aren't accepted, but those are <0.01% of real-world addresses.

3. What `valid: true` doesn't prove

   Syntax-validity is necessary but not sufficient. It does NOT prove the mailbox exists, the domain has MX records, or the user reads it. For a deliverability check, send a confirmation email or use mx-lookup + a real SMTP probe — never a regex.

4. Common false-positives

   `a@b` passes naive checks but fails because the domain has no dot. `foo@bar.` is rejected here for the trailing dot. Plus-addressing (`name+tag@gmail.com`) is valid and the tool accepts it; that's working as intended.