Dave Cridland writes:
I suspect that using a 2xx in this case might be best, since it would become a "discard", in effect, if the LMTP client didn't understand it, and the additional bandwidth and processing for LMTP connections is negligable. For SMTP, a 4xx might be more sensible, which would reduce the bandwidth, but not generate a DSN instantly.
200 2.7.1 Blah blah blah? Arnt