Mail · SMTP, Mail · IMAP and Mail · POP3

These checks confirm the protocol and, optionally, login.

Encryption selection	SMTP	IMAP	POP3
Direct TLS	Port 465	Port 993	Port 995
STARTTLS	Port 587	Port 143	Port 110
No TLS · only without login	Port 25	Port 143	Port 110

The interface adjusts the port when encryption is changed. Username and Password enable a login test. Login requires TLS or STARTTLS.

SMTP checks the greeting, EHLO, TLS and login where applicable, as well as a protocol response. It does not send an email. IMAP does not read or change messages. POP3 does not read or delete messages. The mail checks configured here are separate from the SMTP configuration for notifications.