Enable Internal Relay on Exchange 2007
By default Exchange 2007 will automatically relay emails from clients that authenticate. This is a recommended relay method, however some application may not support authentication.
If you try to send email without authentication you will get SMTP error message "550 5.7.1 Unable to relay"
To enable relay for non-authenticated internal clients:
- Open Exchange Management Console (EMC) > Server Configuration > Hub Transport > Receive Connectors
- Click on "New Receive Connector" in ActionsPanel
- Name: Enter name for your new connector
- Intended Use: Leave default (Custom)
- Local Network Settings: Leave default (all available addresses)
- Remote Network Settings: Remove existing entry and add IP Address(es) of your clients that need to relay.
- Select your new connector > Properties
- Permission Groups (tab): Select Exchange Servers
- Authentication (tab): Select: Transport Layer Security (TLS) and Externally Secured (for example, with IPsec)
MS Exchange 2007
MS Small Business Server 2008 (SBS 2008)
SMTP Response / Error Codes
Most common SMTP Response codes:
200 - | (nonstandard success response, see rfc876) |
211 - | System status, or system help reply |
214 - | Help message |
220 - | SMTP Service ready |
221 - | Service closing transmission channel |
250 - | Requested mail action okay, completed |
251 - | The recipient is not local to the server, but the server will accept and forward the message. |
252 - | The recipient cannot be VRFYed, but the server accepts the message and attempts delivery. |
354 - | Start mail input; end with <CRLF>.<CRLF> |
421 - | Service not available, closing transmission channel |
450 - | Requested mail action not taken: mailbox unavailable |
451 - | Requested action aborted: local error in processing |
452 - | Requested action not taken: insufficient system storage |
500 - | Syntax error, command unrecognised |
501 - | Syntax error in parameters or arguments |
502 - | Command not implemented |
503 - | Bad sequence of commands |
504 - | Command parameter not implemented |
521 - | Server does not accept mail |
530 - | Access denied |
550 - | Requested action not taken: mailbox unavailable |
551 - | User not local; please try forward address |
552 - | Requested mail action aborted: exceeded storage allocation |
553 - | Requested action not taken: mailbox name not allowed |
554 - | Transaction failed |
Increase Receive Connector Timeout on Exchange 2007
Default Receive Connector Timeout is 10min. This is enough in most of the situations however in case of slow / unreliable connection this could cause delivery problems, especially for large emails.
You may get 421 4.4.1 Connection timed out errors in SMTP Receive Connector Protocol logs.
You can increase the timeout using Exchange Management Shell
To check timeout for all SMTP receive connectors:
Get-ReceiveConnector | fl Id*,*connectiontime*
To check timeout for a specific SMTP receive connector:
Get-ReceiveConnector "*ConnectorName*" | fl Id*,*connectiontime*
To set timeout for a specific SMTP receive connector to 30min:
Set-ReceiveConnector "*ConnectorName*" -ConnectionTimeout 00:30:00
Exchange Server 2007
Windows Small Business Server (SBS) 2008
Enable Receive Connector Protocol Logging on Exchange 2007
Standard Exchange Message Tracking from EMC Toolbox is a useful tool and often helps to diagnose message delivery issues. However if message is rejected at Hub Transport level it will not be logged in Message Tracking logs. To trace such messages you need to enable Receive Connector Logging.
Open Exchange Management Console > Server Configuration > Hub Transport > [Receive Connector] > Properties > General > Protocol Logging Level
Change the level from None to Verbose.
By default logs will be saved in :
C:\Program Files\Microsoft\Exchange Server\TransportRoles\Logs\ProtocolLog\SmtpReceive
Make sure you disable logging after troubleshooting is finished.
If you have Edge Transport Server you will need to enable Protocol Logging on Edge Transport Receive Connector as this will be the first place where messages hit your network.
Exchange 2007
Windows Small Business Server (SBS) 2008
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