Email Problem "content-type text/plain charset= utf-8"

Question

We are using Sophos Xg firewall. We are receiving emails from three of our customers and when we open it then found in a different format which is very strange. I attached a screenshot of that message kindly view it and if someone knows the solution then guide me.

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Aeudian · Answer

I was told that this will be resolved in 17.5.4 MR4 and the issue is resides in the malware scanning via my technical case today. The technician I spoke too was unclear if an exception to malware scanning, disabling malware globally, or changing from dual scanning to single scanning would resolve it. 
 
 Sophos has this noted as an Internal Bug: NC-40131