When one user connectes to SMTP to send they get this error: 550 5.7.1 Client does not have permissions to send as this sender The user is authenticated correctly. Other users don't have this issue.In searching through the forums I saw this command: Get-ReceiveConnector "EXCA1\Default EXCA1" | add-adpermission -user AU -extendedrights ms-Exch-SMTP-Accept-Authoritative-Domain-Sender This does allow the user to send, but it also allows all users to send as any other user, and so isn't the sollution I'm looking for. I'm not sure how to continue troubleshooting this, and it's strange that it's just one user (that I know of). Here is the relevant excerpt from the smtp protocol server log: auth login, 334 <authentication response>, 334 <authentication response>, SMTPSubmit SMTPAcceptAnyRecipient BypassAntiSpam AcceptRoutingHeaders,Set Session Permissions domain\user,authenticated 235 2.7.0 Authentication successful, mail from: user@domain.org, 08CB8C7983F681A8;2009-05-11T17:45:37.139Z;1,receiving message 550 5.7.1 Client does not have permissions to send as this sender, jj

how about you disconnect the mailbox and connect it again? Seems like the user missing the self send-as and receive as permission.Arun Kumar | MCSE - 2K3 + Messaging | ITIL-F V3

Andrew,A couple of suggestions;1. Use LDP.exe to dump the user account information into a text file and compare it with other user account with simillar configuration.2. Use powershell to grant user Send As, Recieve As, Read Personal Information and Write Personal Information permissions to SELF account.Additionally, you may try adding the user account itself to the ACL and grant it full permissions to the mailbox though Exchange must have provisioned all those permissions already.MMilind Naphade | MCTS:M | http://www.msexchangegeek.com

I disconnected the user (which is me luckily) and see the mailbox in disconnected mailboxes. When I go through the connect mailbox wizard though it doesn't see my login as a matching user, and doesn't find it in existing users. I do see other users without mailboxes in existing users. Also I should have mentioned that I could send from other non-smtp clients, like outlook, owa and entourage. Just smtp was giving me the problem. Now of course with no mailbox I can't authenticate over smtp at all. I know that self had send as permissions on the mailbox. I don't think I can get ad permissions on it while it's disconnected.

Ok I didn't realize it would delete the user object from AD. I restored using adrestore. I looked at the send as permissions and NT Authority\Self was not there. I added NT Authority\Self to the send as permissions and it seems to be working. Thanks for the help!