When performing message forensics, you may find messages discarded for the reason of "ipblocked." These messages are discarded due to Sophos's Blacklisted Sender IP service. Reasons are identified by expanding the message details from the Mail Logs search pane.

Policy Rule:Sophos Blacklisted Sender IP
Discarded:For reason: ipblocked

What to do:

There are two options that you can use to allow the message to pass (assuming the message is legitimate).

Option 1:

If the IP address is known to be incorrectly detected by our service, follow the link below.

http://www.sophos.com/en-us/threat-center/ip-lookup.aspx

You are taken to the page shown below.

Enter the IP address in the text box, and click Submit. A page will be displayed, explaining the reason the IP was listed by our service.  You then have the opportunity to request that the address be exempt, as shown in the example below.

Option 2:

You can whitelist the host or sender by editing the Allow list in Configuration -> Policy -> Allow/Block lists