meillo@258: -oem
meillo@258: ====
meillo@258: 
meillo@258: This document explains what I found out about the -oem/-oee options. It
meillo@258: is intended as a knowledge base for further development on this topic.
meillo@258: In version 0.3.0 (2010-11), masqmail's implementation of -oem is
meillo@258: considered broken and -oee is not implemented.
meillo@258: 
meillo@258: Following is the behavior masqmail actually had:
meillo@258: 
meillo@258:     If -oi/-i is given, -oem is ignored.
meillo@258:     If no -oi/-i is given, always return with a non-zero return code.
meillo@258: 
meillo@258: This current behavior is not like it should be.
meillo@258: 
meillo@258: 
meillo@258: The desired behavior
meillo@258: --------------------
meillo@258: 
meillo@258: It had been difficult to identify good explanations.  The problem, as
meillo@258: often, is that sendmail's source would be the definitive definition.
meillo@258: But in which version and what if common behavior differs from sendmail's
meillo@258: (maybe as a result of misunderstanding)?  Exim's documentation has proven
meillo@258: to be a valuable resource.
meillo@258: 
meillo@258: In exim the behavior is such:
meillo@258: 
meillo@258:     If an error is detected while a non-SMTP message is being received
meillo@258:     (for example, a malformed address), the error is reported to
meillo@258:     the sender in a mail message.  Exim exits with a non-zero return
meillo@258:     code then, no matter if the error message was successful or not.
meillo@258:     (In exim, -oee is similar but exim returns successful if the error
meillo@258:     message had been sent successful.)
meillo@258: 
meillo@258: The mutt wiki writes about ``sendmail -oi -oem'':
meillo@258: 
meillo@258:     The mail server (in this case sendmail) will receive the message
meillo@258:     in input, and will parse it. In case of a malformed message,
meillo@258:     it will send an error message to the user to whom belongs the
meillo@258:     MUA trasmitting the message (e.g. user@localhost.localdomain),
meillo@258:     and it will exit with a non zero exit code: the -oem flag forces
meillo@258:     the returning of a non zero exit code even in the case the error
meillo@258:     message has been successfully sent to the local server.
meillo@258: 
meillo@258: 
meillo@258: What does it mean for masqmail?
meillo@258: -------------------------------
meillo@258: 
meillo@258: Masqmail does not send error messages on malformed addresses.  It does
meillo@258: not much check for syntax.  It detects general errors (unexpected EOF,
meillo@258: no recipients, max message size exceeded) (see masqmail.c:mode_accept())
meillo@258: but simply prints a message to stderr and exits non-zero.  I think that
meillo@258: currently it is not of need to add some elaborate error handling in
meillo@258: this area.  Hence, for the implementing of -oem and -oee would do assume
meillo@258: that sending the error message does always fail (because we never send
meillo@258: any such message) and hence we exit non-zero on error.  This is the
meillo@258: similar behavior of both options.
meillo@258: 
meillo@258: From 0.3.1 on masqmail will not recognize -oem anymore and thus ignore
meillo@258: it like any unknown -oXXX option. It's behavior is then as if error
meillo@258: message sending fails.
meillo@258: 
meillo@258: Remind that all this affects only the case of accepting non-SMTP messages
meillo@258: on stdin.
meillo@258: 
meillo@258: 
meillo@258: On the relationship of -oi and -oem
meillo@258: -----------------------------------
meillo@258: 
meillo@258: It seems as if the two options should not affect each other; in contrast
meillo@258: to the behavior in masqmail before 0.3.1.  Their relationship is just
meillo@258: that -oem does only affect non-SMTP messages on stdin, which is the
meillo@258: typical use case of -oi.
meillo@258: 
meillo@258: 
meillo@258: meillo