In an exchange 2007 site (well a 2003 site with exch 2007), I can send some messages but not others depending on addressing. The domain name is "chico.com" and any legal address sent to "user@chico.com" fails as undeliverable. Using Telnet server 25, I get the message "client does not have permissions to send as this sender." If I do "mail from:user@exchange.chico.com" everything works as expected, gets OK'd, gets delivered, etc. My receive connectors have no restrictions, that is 0.0.0.0-255.255.255.255 as acceptable for receive from, default authentication plus anonymous has been set. Have removed the Edge Transport server, as it was just .... ============ followup ================ I found an even bigger anomaly with the SMTP issue. I noticed that when using "Telnet server 25" for testing, if I used a bogus address or a mistyped domain in the address, the sender was OK (e.g., user@chico.con or user@junk.com). So I removed the Accepted Domain, after trying both "chico.com" and "*.chico.com", now messages move in and out of the site with no problems. I'm sure I set myself up for relaying with this move.... If any MSFT folks are monitoring this thread, I'd like your response on why this would occur in this manner. It's as if the "Accepted Domain" means refuse SMTP from the named site.thanksBill

check your MX record