From: Claus Aßmann on
Einar Hillbom wrote:

> I have never seen the error message "putbody: write error: Broken pipe"
> when we were running 8.13.1. Now there are several hundreds per day.
> We have a self-made mailer, named pop in the log below, for our virtual
> accounts. The error occurs together with "User unknown" but not always.

Your mailer doesn't read the entire mail, right? See deliver.c.

/*
** Ignore an I/O error that was caused by EPIPE.
** Some broken mailers don't read the entire body
** but just exit() thus causing an I/O error.
*/