Question : Exchange 2010: 550 5.7.1 Client does not have permissions to send as this sender

Hi Experts,

I have trouble sending mail from external, authenticated clients through my Exchange 2010 server. Here's a logfile from an Outlook Express client, sending in to port 587:

SMTP: 19:32:41 [rx] 220 Saturn.IT.zz Microsoft ESMTP MAIL Service ready at Mon, 15 Feb 2010 19:32:48 +0100
SMTP: 19:32:41 [tx] EHLO AnjaPC
SMTP: 19:32:41 [rx] 250-Saturn.IT.zz Hello [84.176.209.205]
SMTP: 19:32:41 [rx] 250-SIZE 10485760
SMTP: 19:32:41 [rx] 250-PIPELINING
SMTP: 19:32:41 [rx] 250-DSN
SMTP: 19:32:41 [rx] 250-ENHANCEDSTATUSCODES
SMTP: 19:32:41 [rx] 250-STARTTLS
SMTP: 19:32:41 [rx] 250-X-ANONYMOUSTLS
SMTP: 19:32:41 [rx] 250-AUTH GSSAPI NTLM LOGIN
SMTP: 19:32:41 [rx] 250-X-EXPS GSSAPI NTLM
SMTP: 19:32:41 [rx] 250-8BITMIME
SMTP: 19:32:41 [rx] 250-BINARYMIME
SMTP: 19:32:41 [rx] 250-CHUNKING
SMTP: 19:32:41 [rx] 250-XEXCH50
SMTP: 19:32:41 [rx] 250-XRDST
SMTP: 19:32:41 [rx] 250 XSHADOW
SMTP: 19:32:41 [tx] AUTH NTLM
SMTP: 19:32:41 [rx] 334 NTLM supported
SMTP: 19:32:41 [tx] ...silly characters...
SMTP: 19:32:42 [rx] 334 ...silly characters...
SMTP: 19:32:42 [tx] ...silly characters...
SMTP: 19:32:47 [rx] 535 5.7.3 Authentication unsuccessful
SMTP: 19:32:47 [tx] AUTH NTLM
SMTP: 19:32:47 [rx] 334 NTLM supported
SMTP: 19:32:47 [tx] ...silly characters...
SMTP: 19:32:47 [rx] 334 ...silly characters...
SMTP: 19:32:47 [tx] ...silly characters...
SMTP: 19:32:47 [rx] 235 2.7.0 Authentication successful
SMTP: 19:32:47 [tx] MAIL FROM:
SMTP: 19:32:47 [rx] 250 2.1.0 Sender OK
SMTP: 19:32:47 [tx] RCPT TO:
SMTP: 19:32:47 [rx] 250 2.1.5 Recipient OK
SMTP: 19:32:47 [tx] DATA
SMTP: 19:32:47 [rx] 354 Start mail input; end with .
SMTP: 19:32:47 [tx]
.
SMTP: 19:32:47 [rx] 550 5.7.1 Client does not have permissions to send as this sender

It does work once I put the sending user into the domain administrators group, but that's not a viable solution.

I have tried the Add-AdPermission -Identity "Default Receive Connector" -User "NT AUTHORITY\Authenticated Users" -ExtendedRights ms-Exch-SMTP-Accept-Any-Sender command, but that made no change either.

I have also checked if the user's SendAs permissions are correct - they did contain the SELF entry, and also adding the user to the list made no difference either.

Do you have any suggestions what I could do next?

Thanks for your help!

Thomas

Answer : Exchange 2010: 550 5.7.1 Client does not have permissions to send as this sender

Silly me.... I had overlooked that the sender's domain was not in the list of accepted domains. (I have around two dozen domains in that list, and just that one was forgotten when I set up the server.)