Symptoms
- The same messages are repeatedly downloaded from the ISP but the messages are never received.
- The Event log shows the same messages being repeatedly sent and received.
- WorkgroupMail can become slow, unresponsive and may crash.
Cause
WorkgroupMail is configured to relay messages received for unknown recipients for the domain. If the recipient is not recognised then the message will be relayed out to the internet. If the message is addressed to your domain then it may be delivered back to the ISP to be downloaded once more. This can continue in a loop where the ‘Received’ message headers keep growing in size.
Resolution
Remove the setting to relay messages for unknown users for your domain. To do this double click the domain in the Administrator and select the Unknown Recipients’ tab. Uncheck the box to Relay the message. Incoming messages to unknown addresses at this domain will now be delivered to the default account.
Note, if the option is set to ‘Relay the message if the recipient is in the routing table’ then leave the setting as found and instead check the routing table entries. Double click Settings in the Administrator and select the routing tab.
More Info
The option to ‘Relay the message if the recipient is in the routing table’ is sometimes used to route outgoing messages to recipients with the same domain address that exist elsewhere on the internet. When doing this you must ensure that the mail server responsible for this domain address will know to route such messages onwards to the correct recipient. More Information
Note: The option to ‘Relay the message Always’ must be used with caution as in the majority of cases this will cause looping as described above.