From 2b1cd09eae8aa7516f8d47a6ee80e92cba714224 Mon Sep 17 00:00:00 2001 From: Ken Hornstein Date: Fri, 16 Mar 2012 00:21:35 -0400 Subject: [PATCH] Update post(8) regarding the New World Order. --- man/post.man | 94 +++++++++++++++++++--------------------------------------- 1 file changed, 30 insertions(+), 64 deletions(-) diff --git a/man/post.man b/man/post.man index 460bd81..5084ec4 100644 --- a/man/post.man +++ b/man/post.man @@ -55,8 +55,8 @@ with acting as a relatively simple preprocessor. Thus, it is .B post -which parses the various header fields, appends -\*(lqFrom:\*(rq and \*(lqDate:\*(rq lines, and interacts with the mail transport system. +which parses the various header fields, appends a +\*(lqDate:\*(rq line, and interacts with the mail transport system. .B Post will not normally be called directly by the user. .PP @@ -122,72 +122,38 @@ delivery). .PP Under normal circumstances, .B post -constructs the \*(lqFrom:\*(rq line of the -message from the user's login name, the full name from the GECOS field of the -passwd file, and the fully\-qualified name of the local machine (or the -value of -\*(lqlocalname\*(rq in -.IR mts.conf , -if set). An example is \*(lqFrom: Dan Harkless -\*(rq. There are four ways to override these values, -however. Note that they apply equally to \*(lqResent\-From:\*(rq lines in messages sent +uses the \*(lqFrom:\*(rq line in the message draft as the identity of +the the originating mailbox. A \*(lqFrom:\*(rq line is required in +all message draft. By default the message composition utilities such +as +.B comp +and +.B repl +will automatically place a \*(lqFrom:\*(rq line in the message draft. +There are two ways to override this behavior, however. +Note that they apply equally to \*(lqResent\-From:\*(rq lines in messages sent with .BR dist . .PP -The first way is GECOS\-based username masquerading. If the \*(lqmasquerade:\*(rq line -in -.I mts.conf -contains \*(lqmmailid\*(rq, this processing is activated. If a user's GECOS -field in the passwd file is of the form \*(lqFull Name \*(rq then \*(lqfakename\*(rq -will be used in place of the real username. For instance, a GECOS field of \*(lqDan -Harkless \*(rq would result in \*(lqFrom: Dan Harkless -\*(rq. Naturally if you were doing something like -this you'd want to set up an MTA alias (e.g. in /etc/aliases) from, for -instance, \*(lqDan.Harkless\*(rq to \*(lqdan\*(rq. -.PP -The second way to override default construction of \*(lqFrom:\*(rq is to set the -.B $SIGNATURE -environment variable. This variable overrides the full name -from the GECOS field, even if GECOS\-based masquerading is being done. This -processing is always active, and does not need to be enabled from -.IR mts.conf . -.PP -The third way is controlled by the \*(lquser_extension\*(rq value of \*(lqmasquerade:\*(rq line -of -.IR mts.conf . -When that's turned on, setting the -.B $USERNAME_EXTENSION -environment variable will result in its value being appended the user's login -name. For instance, if I set -.B $USERNAME_EXTENSION -to \*(lq+www\*(rq, my \*(lqFrom:\*(rq -line will contain \*(lqDan Harkless \*(rq (or -\*(lqDan.Harkless+www\*(rq if I'm using mmailid masquerading as well). Recent versions -of -.B sendmail -automatically deliver all mail sent to -.IR user + string -to -.IR user . -.B qmail -has a similar feature which uses '\-' as the delimiter by -default, but can use other characters as well. +The first way is to supply a \*(lqSender:\*(rq line. The value of this +field will be used as the originating mailbox identity when submitting the +message to the mail transport system. If multiple addresses are +given in the \*(lqFrom:\*(rq line, a \*(lqSender:\*(rq line is +.BR required . +If an \*(lqEnvelope-From:\*(rq line is supplied when multiple addresses +are given in the \*(lqFrom:\*(rq line, a \*(lqSender:\*(rq header will +be generated using the value of the \*(lqEnvelope-From:\*(rq line, +.B if +the \*(lqEnvelope-From:\*(rq line is not blank. .PP -The fourth method of address masquerading is to specify a \*(lqFrom:\*(rq line manually -in the message draft. It will be used as provided (after alias substitution), -but normally, to discourage email forgery, the user's -.B real -address will be -used in the SMTP envelope \*(lqFrom:\*(rq and in a \*(lqSender:\*(rq header. However, if the -\*(lqmasquerade:\*(rq line of -.I mts.conf -contains \*(lqdraft_from\*(rq, the SMTP envelope \*(lqFrom:\*(rq -will use the address given in the draft \*(lqFrom:\*(rq, and there will be no \*(lqSender:\*(rq -header. This is useful in pretending to send mail \*(lqdirectly\*(rq from a remote POP3 -account, or when remote email robots give improper precedence to the envelope -\*(lqFrom:\*(rq. Note that your MTA may still reveal your real identity (e.g. -.BR sendmail 's -\*(lqX\-Authentication\-Warning:\*(rq header). +The second way is to supply a \*(lqEnvelope-From:\*(rq line. The value +of this field will be used as the originating mailbox identity when +submitting the message to the mail transport system. This will override +both the value of the \*(lqFrom:\*(rq line and a \*(lqSender:\*(rq line +(if one is supplied). The \*(lqEnvelope-From:\*(rq line is allowed to +have a blank value; if the value is blank, then the mail transport system +will be instructed to not send any bounces in response to the message. +Not all mail transport systems support this feature. .PP If nmh is using the SMTP MTA, the .B \-server -- 1.7.10.4