Microsoft Exchange Email Relay Error in Drupal
Using a Microsoft Exchange relay/SMTP server to send email can sometimes egenerate error "550 5.7.1 Relaying prohibited". As explained in the Microsoft Knowledgebase at: http://support.microsoft.com/?kbid=304897 this can be caused by a multitude of cases in which the client is not able to properly access adn use the Exchange Relay.
In the case at hand, having configured and tested a Windows Apache MySQL and PHP / WAMP web server and tested it to send email, taking it outside the firewall into the DMZ for web service caused the below error in the Drupal Watchdog along with a long delay in operations that require the sending of email messages.
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| Type | error |
|---|---|
| Date | Thursday, May 25, 2006 - 10:28 |
| User | |
| Location | |
| Message | Error sending email: Language string failed to load: connect_host From: sender@oursever.com To: recepient@domain.com |
| Severity | notice |
| Hostname | xx.xx.xx.61.45 |
Points to consider
Make sure that you have specified the authentication information for your SMTP server in SMTPmail or if you are using the SMTP module in Drupal, make sure that you enter the necessary information
Ensure that the IP address of the web server is specified in the list of allowed clients/senders for the Microsoft Exchange email Relay/SMTP server
Make sure that you do not have the windows firewall or any other firewall running on your web server machine that could be blocking the access through certain ports
