# smtp

## NAME



           **smtp** — Simple Mail Transfer Protocol client
    


## SYNOPSIS



           **smtp**[**-Chnv**] [**-a** _authfile_] [**-F** _from_] [**-H** _helo_] [**-s** _server_] [**-T**
           _params_] [_recipient ..._]
    


## DESCRIPTION



           The **smtp** utility is a Simple Mail Transfer Protocol (SMTP) client
           which can be used to run an SMTP transaction against an SMTP
           server.
    
           By default, **smtp** reads the mail content from the standard input,
           establishes an SMTP session, and runs an SMTP transaction for all
           the specified recipients.  The content is sent unaltered as mail
           data.
    
           The options are as follows:
    
           **-a** _authfile_
                   Perform a login before sending the message.  The username
                   and password are read from _authfile_ and need to be on the
                   first and second line respectively.  This option requires
                   a TLS or STARTTLS _server_.
    
           **-C** Do not require server certificate to be valid.  This flag
                   is deprecated.  Use “**-T noverify** ” instead.
    
           **-F** _from_
                   Set the return-path (MAIL FROM) for the SMTP transaction.
                   Default to the current username.
    
           **-H** _helo_
                   Define the hostname to advertise (HELO) when establishing
                   the SMTP session.
    
           **-h** Display usage.
    
           **-n** Do not actually execute a transaction, just try to
                   establish an SMTP session and quit.  When this option is
                   given, no message is read from the standard input.
    
           **-s** _server_
                   Specify the server to connect to and connection
                   parameters.  The format is
                   [_proto_ ://[_user_ :_pass_ @]]_host_[:_port_].  The following
                   protocols are available:
    
                   smtp        Normal SMTP session with opportunistic
                               STARTTLS.
                   smtp+tls    Normal SMTP session with mandatory STARTTLS.
                   smtp+notls  Plain text SMTP session without TLS.
                   lmtp        LMTP session with opportunistic STARTTLS.
                   lmtp+tls    LMTP session with mandatory STARTTLS.
                   lmtp+notls  Plain text LMTP session without TLS.
                   smtps       SMTP session with forced TLS on connection.
    
                   Defaults to “smtp://localhost:25”.
    
           **-T** _params_
                   Set specific parameters for TLS sessions.  The _params_
                   string is a comma or space separated list of options.  The
                   available options are:
    
                   **cafile** =_filename_
                           Use _filename_ as root certificates file instead of
                           the system default.
    
                   **ciphers** =_value_
                           Specify the allowed ciphers.  Refer to
                           _tls_config_set_ciphers_(3) for _value_.
    
                   **nosni** Disable Server Name Indication (SNI).
    
                   **noverify**
                           Do not require server certificate to be valid.
    
                   **protocols** =_value_
                           Specify the protocols to use.  Refer to
                           _tls_config_parse_protocols_(3) for _value_.
    
                   **servername** =_value_
                           Use _value_ for Server Name Indication (SNI).
                           Defaults to the specified server hostname.
    
           **-v** Be more verbose.  This option can be specified multiple
                   times.
    


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