1.\" $OpenBSD: smtp.1,v 1.14 2021/05/23 16:12:56 eric Exp $ 2.\" 3.\" Copyright (c) 2018, Eric Faurot <eric@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: May 23 2021 $ 18.Dt SMTP 1 19.Os 20.Sh NAME 21.Nm smtp 22.Nd Simple Mail Transfer Protocol client 23.Sh SYNOPSIS 24.Nm 25.Op Fl Chnv 26.Op Fl a Ar authfile 27.Op Fl F Ar from 28.Op Fl H Ar helo 29.Op Fl s Ar server 30.Op Fl T Ar params 31.Op Ar recipient ... 32.Sh DESCRIPTION 33The 34.Nm 35utility is a Simple Mail Transfer Protocol 36.Pq SMTP 37client which can be used to run an SMTP transaction against an SMTP server. 38.Pp 39By default, 40.Nm 41reads the mail content from the standard input, establishes an SMTP session, 42and runs an SMTP transaction for all the specified recipients. 43The content is sent unaltered as mail data. 44.Pp 45The options are as follows: 46.Bl -tag -width Ds 47.It Fl a Ar authfile 48Perform a login before sending the message. 49The username and password are read from 50.Ar authfile 51and need to be on the first and second line respectively. 52This option requires a TLS or STARTTLS 53.Ar server . 54.It Fl C 55Do not require server certificate to be valid. 56This flag is deprecated. 57Use 58.Dq Fl T Cm noverify 59instead. 60.It Fl F Ar from 61Set the return-path (MAIL FROM) for the SMTP transaction. 62Default to the current username. 63.It Fl H Ar helo 64Define the hostname to advertise (HELO) when establishing the SMTP session. 65.It Fl h 66Display usage. 67.It Fl n 68Do not actually execute a transaction, 69just try to establish an SMTP session and quit. 70When this option is given, no message is read from the standard input. 71.It Fl s Ar server 72Specify the server to connect to and connection parameters. 73The format is 74.Sm off 75.Op Ar proto No :// Op Ar user : pass No @ 76.Ar host Op : Ar port . 77.Sm on 78The following protocols are available: 79.Pp 80.Bl -tag -width "smtp+notls" -compact 81.It smtp 82Normal SMTP session with opportunistic STARTTLS. 83.It smtp+tls 84Normal SMTP session with mandatory STARTTLS. 85.It smtp+notls 86Plain text SMTP session without TLS. 87.It lmtp 88LMTP session with opportunistic STARTTLS. 89.It lmtp+tls 90LMTP session with mandatory STARTTLS. 91.It lmtp+notls 92Plain text LMTP session without TLS. 93.It smtps 94SMTP session with forced TLS on connection. 95.El 96.Pp 97Defaults to 98.Dq smtp://localhost:25 . 99.It Fl T Ar params 100Set specific parameters for TLS sessions. 101The 102.Ar params 103string is a comma or space separated list of options. 104The available options are: 105.Bl -tag -width Ds 106.It Cm cafile Ns = Ns Ar filename 107Use 108.Ar filename 109as root certificates file instead of the system default. 110.It Cm ciphers Ns = Ns Ar value 111Specify the allowed ciphers. 112Refer to 113.Xr tls_config_set_ciphers 3 114for 115.Ar value . 116.It Cm nosni 117Disable Server Name Indication (SNI). 118.It Cm noverify 119Do not require server certificate to be valid. 120.It Cm protocols Ns = Ns Ar value 121Specify the protocols to use. 122Refer to 123.Xr tls_config_parse_protocols 3 124for 125.Ar value . 126.It Cm servername Ns = Ns Ar value 127Use 128.Ar value 129for Server Name Indication (SNI). 130Defaults to the specified server hostname. 131.El 132.It Fl v 133Be more verbose. 134This option can be specified multiple times. 135.El 136.Sh SEE ALSO 137.Xr smtpd 8 138.Sh HISTORY 139The 140.Nm 141program first appeared in 142.Ox 6.4 . 143