The check_smtp Plugin

check_smtp v2.3git (monitoring-plugins 2.3git)
Copyright (c) 1999-2001 Ethan Galstad <>
Copyright (c) 2000-2007 Monitoring Plugins Development Team

This plugin will attempt to open an SMTP connection with the host.

check_smtp -H host [-p port] [-4|-6] [-e expect] [-C command] [-R response] [-f from addr]
[-A authtype -U authuser -P authpass] [-w warn] [-c crit] [-t timeout] [-q]
[-F fqdn] [-S] [-L] [-D warn days cert expire[,crit days cert expire]] [-v]

 -h, --help
    Print detailed help screen
 -V, --version
    Print version information
    Read options from an ini file. See
    for usage and examples.
 -H, --hostname=ADDRESS
    Host name, IP Address, or unix socket (must be an absolute path)
 -p, --port=INTEGER
    Port number (default: 25)
 -4, --use-ipv4
    Use IPv4 connection
 -6, --use-ipv6
    Use IPv6 connection
 -e, --expect=STRING
    String to expect in first line of server response (default: '220')
 -C, --command=STRING
    SMTP command (may be used repeatedly)
 -R, --response=STRING
    Expected response to command (may be used repeatedly)
 -f, --from=STRING
    FROM-address to include in MAIL command, required by Exchange 2000
 -F, --fqdn=STRING
    FQDN used for HELO
 -D, --certificate=INTEGER[,INTEGER]
    Minimum number of days a certificate has to be valid.
 -S, --starttls
    Use STARTTLS for the connection.
 -A, --authtype=STRING
    SMTP AUTH type to check (default none, only LOGIN supported)
 -U, --authuser=STRING
    SMTP AUTH username
 -P, --authpass=STRING
    SMTP AUTH password
 -L, --lmtp
    Send LHLO instead of HELO/EHLO
 -q, --ignore-quit-failure
    Ignore failure when sending QUIT command to server
 -w, --warning=DOUBLE
    Response time to result in warning status (seconds)
 -c, --critical=DOUBLE
    Response time to result in critical status (seconds)
 -t, --timeout=INTEGER
    Seconds before connection times out (default: 10)
 -v, --verbose
    Show details for command-line debugging (output may be truncated by
    the monitoring system)

Successul connects return STATE_OK, refusals and timeouts return
STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful
connects, but incorrect response messages from the host result in
STATE_WARNING return values.

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use of this software. To submit patches or suggest improvements, send email