Mail server checks Beta
POST /api/v1/monitors
Types smtp, pop3 and imap: connect to a mail server, read its greeting, and optionally sign in. They work the same way, so they share this page.
There is no separate endpoint for this: it is the ordinary create a monitor call with type set to "smtp", "pop3" or "imap". The same settings apply when you update a monitor with PATCH /api/v1/monitors/{id}.
Every type shares the same interval, retries, alerting, maintenance, results and reports. Only the settings below differ. See Check types for how the nine types compare.
Up or down
- Up when the server answers with a healthy greeting:
2xxfor SMTP,+OKfor POP3,* OKfor IMAP. Anything else is The server refused the connection. - With
expectString, the greeting must also contain that text. Useful for catching a server that answers but announces the wrong host name. - With
encryption: "starttls", the check upgrades the connection after the greeting and goes down if the server won't. - For SMTP only, setting
authUsernameandauthPasswordmakes the check sign in, so it proves a mailbox still works rather than that the port answers. A refused sign-in is down. - The response time is the time to the greeting.
Ports and encryption
Leave port out and the standard port for the encryption you chose is used:
| Type | none or starttls | tls |
|---|---|---|
smtp | 25 | 465 |
pop3 | 110 | 995 |
imap | 143 | 993 |
none: plain connection.tls: encrypted from the start, on the TLS port.starttls: plain connection, upgraded after the greeting.- Set
portyourself for anything else, such as submission on 587 withstarttls.
Settings that apply
| Setting | Notes |
|---|---|
url required | The mail host, for example mail.example.com. Not a URL. |
port | Optional. Falls back to the table above. |
encryption | none (default), tls or starttls. |
expectString | Text the greeting must contain. Up to 500 characters. |
authUsername, authPassword | SMTP only. Sign in as this mailbox. The password is write-only and stored encrypted. |
timeoutSeconds | How long to wait for the connection and each reply. |
Create one
An IMAP server on the standard TLS port:
Submission on 587, upgrading to TLS and signing in, so the check fails if the mailbox stops working:
Related
- DNS record check: check the MX records too
- TCP port check: for a port with no protocol to speak
- Monitor settings: every field in full