Nigel Metheringham edited this page Nov 29, 2012 · 2 revisions

Q0612

Question

Why does the pipe transport add a line starting with >From to messages?

Answer

Actually, it adds a line starting with From followed by a space. This is commonly referred to as the From_ line, to emphasize the fact that From is followed by a space and not a colon. This is a pseudo-header line that contains the envelope sender address and the time of delivery. It originated as a separator line in Berkeley format mailboxes, but is also used in other contexts. (And yes, it is often confused with the From: header line, and this causes a lot of grief. The use of From_ was one of the really bad email design decisions.) Exim's pipe transport adds this pseudo-header line by default because /usr/ucb/vacation needs it, and that is one of the the most common uses of piping. The procmail local delivery agent also makes use of the From_ line. If you do not want it, change the setting of message_prefix on the pipe transport. For example, to remove the line altogether, use

message_prefix =

If you are not piping to /usr/ucb/vacation or procmail, it is likely that you do not need a From_ line, and indeed it may cause problems if it is present. One user reported that this line gave trouble when a pipe was used to send messages to Courier's deliverquota program. The line was retained with the message, and caused problems for MS Exchange 2000 when retrieving messages with its built-in POP collector. Specifically, it caused Exchange to not be able to recognise message attachments.


Clone this wiki locally
You can’t perform that action at this time.
You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.
Press h to open a hovercard with more details.