1.\" $OpenBSD: forward.5,v 1.12 2024/09/05 06:33:04 jmc Exp $ 2.\" 3.\" Copyright (c) 2012 Gilles Chehade <gilles@poolp.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: September 5 2024 $ 18.Dt FORWARD 5 19.Os 20.Sh NAME 21.Nm forward 22.Nd email forwarding information file 23.Sh DESCRIPTION 24Users may put a 25.Nm .forward 26file in their home directory. 27If this file exists, 28.Xr smtpd 8 29forwards email to the destinations specified therein. 30.Pp 31A 32.Nm .forward 33file contains a list of expansion values, as described in 34.Xr aliases 5 . 35Each expansion value should be on a line by itself. 36Expansion is performed under the user ID of the 37.Nm .forward 38file owner. 39.Pp 40Permissions on the 41.Nm .forward 42file are very strict and expansion is rejected if the file is 43group or world-writable; 44if the home directory is group writeable; 45or if the file is not owned by the user. 46.Pp 47Users should avoid editing the 48.Nm .forward 49file directly, to prevent delivery failures from occurring if a message 50arrives while the file is not fully written. 51The best option is to use a temporary file and use the 52.Xr mv 1 53command to atomically overwrite the former 54.Nm .forward . 55Alternatively, setting the 56.Xr sticky 8 57bit on the home directory will cause the 58.Nm .forward 59lookup to return a temporary failure, causing mails to be deferred. 60.Sh FILES 61.Bl -tag -width "~/.forwardXXX" -compact 62.It Pa ~/.forward 63Email forwarding information. 64.El 65.Sh EXAMPLES 66The following file forwards mail to 67.Dq user@example.com , 68and pipes the same mail to 69.Dq examplemda . 70.Bd -literal -offset indent 71# empty lines are ignored 72 73user@example.com # anything after # is ignored 74"|/path/to/examplemda" 75.Ed 76.Sh SEE ALSO 77.Xr aliases 5 , 78.Xr smtpd 8 79.Sh CAVEATS 80The pipe 81.Sq | 82and :include: mechanisms are not allowed for the root user. 83