I still don't get it: why is that smiley face added there in the first place? The mysterious J appears in emails from people that certainly wouldn't 'sign' their email with a smiley face.
Outlook auto-corrects a variety of smiley-type -- :) :-) etc. -- into the aforementioned J.
That still doesn't explain why it would be in a message from someone who wouldn't use a smiley in the first place.
How do you know they didn't intend to enter a smiley face?
Because he never gets smiley faces from them. Of course, he gets a suspicious number of Js.
Well, there have been people whose emails would consistently end in a J on a single line. And these aren't people that would end their mails with a single smiley on the last line. Some of them probably don't even know what a smiley is.