Bind SMTP Server to Address: Specifies what adapters or IP addresses on the server Alligate should listen for connections on. Usually, "All" is acceptable unless you have a specific need to bind to a certain address.
Port: Specifies the TCP port that Alligate will listen on, on the bound interfaces.
Queue Forward Threads: Specifies the number of threads that Alligate should allocate for forwarding mail to the destination server. This seldom needs to be changed and in no case should a value in excess of 4 or 5 be necessary.
Queue Check Interval: Specifies how often Alligate should poll the Queue for messages waiting to be delivered.
Return 421 errors with CPU usage exceeds: Specifies the amount of CPU usage in percent that would tell Alligate that it should should start returning 421 errors to remote servers, so they can re-queue their mail and reduce the load on your server. As soon as the CPU level drops below the specified criteria, normal mail processing will resume. This is very helpful for systems that mat experience high CPU loads. It gracefully tells the remote sender that your server is under a high load and to please try again later. Spammers will usually never try again, but legitimate mail servers will try again in a few minutes.
Remote Client Timeout: Specifies the amount of time that Alligate should stay connected with a remote SMTP server that is sending mail to a local domain before it disconnects from the remote server. If no activity is detected by the time the timeout expires, the connection will be terminated.
Forwarding Thread Timeout: Specifies the amount of time that Alligate should try to forward a message to your mail server before it gives up and re-queues the message.
Recipient verification Thread Timeout: Specifies the amount of time that Alligate should try to validate a recipient on your destination SMTP server before it gives up. In this case, the message will still be accepted and recipient checking will be done again on delivery.
Attempt mail delivery for x hours: This option specifies how long Alligate should try to resend messages that it wasn't able to be delivered to the destination server. If they are still undeliverable after the number of hours you specify they will be moved to the ..\Alligate\Badmail folder.
Attempt mail delivery every x minutes: This option specifies how often Alligate should try to resend messages that it wasn't able to be delivered to the destination server. Messages that are temporarily undeliverable will be maintained in the ..\Alligate\Route folder.
Send bounce messages after timeouts expire: Specifies whether Alligate should send bounce messages to the sender of a message if delivery is not successful after the maximum time period expires.