Check manual page of check_mail_loop
POP3/IMAP connection and optional mail forwarding
Sends out special eMails to a defined mail address using the SMTP protocol
and then tries to receive these mails back by querying the inbox of a IMAP
or POP3 mailbox.
With this check you can verify that your whole mail delivery progress is working.
This check can be configured using WATO.
No discovery supported.