Senders

Field	Description
Score messages where sender's domain does not exist	Check this option IceWarp Server to check whether the sender's domain exists. If it does not, IceWarp Server will increase the spam score by the value specified.
Score messages where HELO host does not resolve to remote IP	Check this option and IceWarp Server will check whether the hostname given in the HELO command resolves to the same IP address that the message is being delivered from. If it does not, IceWarp Server will increase the spam score by the value specified.
Score messas where SMTP callback verification fails	Check this option IceWarp Server to verify whether the IP address that is delivering the message is a valid SMTP server. If it does not, IceWarp Server will increase the spam score by the value specified. Warning: This is achieved by attempting to connect to port 25 (the standard SMTP port) of the domain this message is coming from. A response to this could take up to 5 seconds and could therefore seriously slow down your server.

Score messages where sender's domain does not exist

Check this option IceWarp Server to check whether the sender's domain exists.

If it does not, IceWarp Server will increase the spam score by the value specified.

Score messages where HELO host does not resolve to remote IP

Check this option and IceWarp Server will check whether the hostname given in the HELO command resolves to the same IP address that the message is being delivered from.

If it does not, IceWarp Server will increase the spam score by the value specified.

Score messas where SMTP callback verification fails

Check this option IceWarp Server to verify whether the IP address that is delivering the message is a valid SMTP server.

If it does not, IceWarp Server will increase the spam score by the value specified.

Warning: This is achieved by attempting to connect to port 25 (the standard SMTP port) of the domain this message is coming from. A response to this could take up to 5 seconds and could therefore seriously slow down your server.