i hopee this is the issue
usuallly filename followed by a dot will be the file extension of that file
as you have used multiple dot symbol it shows this error
may i know why you want to use . in the file name
if not necessary we can use as @sandeep13 suggested
You can replace the special characters from the attachment name.
Use replace activity and remove the special characters.
I have taken the first mail’s first attachment’s name
Use regex “\|/|:|*|?|"|<|>||”