UserGate Mail Server

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Sender Filtering

 
UserGate Mail Server starts sender filtering after the MAIL FROM command has been received. If the address in the MAIL FROM command is a blank address (“<>”), UserGate Mail Server will complete the Backscatter check. This check is used, for example, to block “fake” information messages, such as delivery failure messages. Backscatter settings (“Antispam – Backscatter” page) should specify the address of the server used for the check and an exceptions list.
 
If the MAIL FROM command does not contain a blank address, UserGate Mail Server will scan the black and white lists for this address. If the address is found on the black list, UserGate Mail Server will close the incoming connection and produce a corresponding error message. If the address is on the white list, all subsequent checks will be skipped.
 
The next step is to check if the domain whose address is listed in the MAIL FROM command has an MX (Mail eXchanger) record and a SPF (Sender Policy Framework) record. To enable MX record check, go to “Antispam – Settings” page of the administrator console. SPF check parameters are assigned in the Antispam section of the corresponding SPF page. You can set UserGate Mail Server to respond to the results of MX and SPF checks in the server settings.
 
The last step is to complete RHSBL filtering by the domain name listed in the MAIL FROM command. If the domain name is found on the spam list, UserGate Mail Server will close the incoming connection and produce a corresponding error message.