Hello Team,
Yes you can add this for emails which contains a virus if you wish.
I would assume your AV engine would not be dropping the emails but set to deliver for viral affected emails?
If so you will need to go to your AV settings for your policies ( GUI > mail policies > incoming mail policies) and add an extra header for when the AV engine gets triggered as viral to add a header like X-ESA-Viral : true
Then run a content filter that will look for the X-ESA-Viral header with value -> true
Then add a 'header' to the email which will put the text on the top of the email (a footer will put it at the end of the email) and the header can use a disclaimer resource (A custom disclaimer can be created for usage in GUI > mail policies > text resources).
Regards,
Matthew