Tool · Mail
SMTP, without sending mail
We resolve MX if you paste an email, otherwise we hit the host. Banner, EHLO, STARTTLS. No AUTH. If someone asks for the mailbox password “for a test”, that is not this tool.
When it helps
A form “does not send”. Before rewriting PHP, see if 587 answers and offers STARTTLS. Often the hoster just closed outbound SMTP.
Port 25 is filtered on many VPS, including ours at times. Fail on 25 and OK on 587 is not a bug in the tool.
What we try
- MX
- An address uses the lowest-preference MX. A smtp.* host is tested as-is.
- 587
- Submission. We want a 2xx banner and STARTTLS.
- 465
- TLS first, then EHLO. Still around on older relays.
- 25
- Classic relay. Often closed outbound. We try; a timeout is normal.
What we will not do
No credentials, no real MAIL FROM, no message. EHLO it-empower.com then QUIT.
No port ranges. 25, 465, 587. Internal hosts are refused after DNS.
In practice
Gmail is OK and my VPS is silent?
- Theirs is open. Yours may sit behind a security group, or you tested the apex instead of smtp.your-domain.
No STARTTLS — should I care?
- Yes on a current relay. A later AUTH would ride in the clear. Fix that before you put a password on it.
Can you send a test mail?
- No, and we will not add that here. Too easy to abuse. A real send is a job, with your accounts.
Around this
If MX points at last year’s host, mail never reaches you — that is unrelated to HTTPS.