Hi, If I send a simple gmail To: Joe He'll get the email just fine. If I send a simple gmail To: Joe, Sally I will get the following error message: Delivery to the following recipient failed permanently: Joe@mydomain.com Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 501 501 5.5.4 Unrecognized parameter (state 15). The email is not logged in Exchange or the spam software (GFI). Some international email never arrives either. Is there a setting that could be kicking out some of our email? It appears 2003 was an upgrade from 5.5. Thanks for your time. Bruce

That isn't an Exchange message. What is between Exchange and the Internet? A firewall? Check it isn't scanning SMTP email. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Hi, What does the following sentence mean? “If I send a simple gmail To: Joe He'll get the email just fine. If I send a simple gmail To: Joe, Sally I will get the following error message” I would like to confirm when the error message occurs. Does the message occur if you send an e-mail from your Gmail to Exchange mailbox? If so, can you use another mail to send a test message to your Exchange mailbox, such as Hotmail? Regarding to the error message, I suspect it is caused by Authentication settings. I suggest you enable the Anonymous access in the Authentication setting of Default SMTP virtual server to check the result. Thanks. NovakPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.