An exit value of EX_IOERR (the value 74)
means that a serious operating system error occurred. This class of
error relates mostly to disk I/O.
If the body of a mail message could not be read, the following error
message is logged:
putbody: dir/dfqid: read error
The file might have vanished because of a disk crash and might have
been restored to lost+found. The
dir is the queue directory, and the
qid is the queue identifier that will help you
to find the qf file. Inside that
qf file is an I line that gives
the inode and major and minor device numbers of the disk that held
the df file (I line).
An error that occurs while writing to the
pipe(2) connection to a delivery agent causes
the following error to be logged and the
fork(2)'d child to exit with
EX_CONFIG:
putbody: write error
