On Mon, 10 Apr 2006 15:40:44 EDT, "Gartner, James" said: > Folks, > What is the difference between a BOUNCE, and a SOFTBOUNCE in a bounce > report?? > For example: > 20060406103345 BOUNCE [log in to unmask] 5.1.1 Mailer vaemail2.abc.com > said: "550 5.1.1 <[log in to unmask]>... User unknown" > 20060406103626 SOFTBOUNCE [log in to unmask] 5.3.0 553 5.3.0 > <[log in to unmask]>... Unknown user - sorry. A BOUNCE is, in SMTP parlance, the response from a "permanently failed" attempt that will in all likelyhood *not* succeed until a human takes manual intervention (for instance, a "no such user" error, end user mailbox full, or a permanent permissions issue on a mailbox). A 'Soft Bounce' is a *temporary* failure that has a high chance of succeeding if retried - network outages, full spool disks on the inbound receiving area, excessive mail server load, and so on... Having said that, I'm not clear why your example got flagged as a 'softbounce' - usually failures have 5XX and 5.y.z errors, while temp fails have 4XX and 4.y.z codes (in fact, the 4/5 distinction is defined as how to tell one from the other).