On Thu, Apr 22, 2010 at 06:35:52PM -0400, Bill Cole wrote: >> In: DATA >> Out: 354 End data with<CR><LF>.<CR><LF> >> Out: 451 4.3.0 Error: queue file write error > > http://www.postfix.org/SMTPD_PROXY_README.html explains one possible source > of this: inability to connect to a before-queue proxy.
This is quite possible. > Others include permissions and storage space issues with your queue > directory and various other configuration errors. What is sent back to the > client in this class of circumstances is documented as being "intentionally > vague" so you really do need to look at the log for useful info. Right, a transient error storing the data into the queue, that is not message too large (so missing ESMTP SIZE is probably not it...) static const CLEANUP_STAT_DETAIL cleanup_stat_map[] = { CLEANUP_STAT_DEFER, 451, "4.7.1", "service unavailable", CLEANUP_STAT_PROXY, 451, "4.3.0", "queue file write error", CLEANUP_STAT_BAD, 451, "4.3.0", "internal protocol error", CLEANUP_STAT_RCPT, 550, "5.1.0", "no recipients specified", CLEANUP_STAT_HOPS, 554, "5.4.0", "too many hops", CLEANUP_STAT_SIZE, 552, "5.3.4", "message file too big", CLEANUP_STAT_CONT, 550, "5.7.1", "message content rejected", CLEANUP_STAT_WRITE, 451, "4.3.0", "queue file write error", }; Anyway the OP's original post clearly included text that advised him to read his logs for more details. There would have been no need to guess at the cause had this advice not been ignored. -- Viktor. P.S. Morgan Stanley is looking for a New York City based, Senior Unix system/email administrator to architect and sustain our perimeter email environment. If you are interested, please drop me a note.