Well there is most certainly some confusion in this topic as Alan said my reply was in response to his post on using a registry hack to stop OE blocking .exe files, etc.
Today is the first time I have seen Reply #16 to #21 which were posted before my reply in #22 so I haven't a clue what is going on. The forums post function usually blocks the post if there has been a reply whilst you were compiling a response to allow you to read those replies and modify or even delete that response.
So perhaps we can this to the search inconsistencies that Alan has recently commented on
I hadn't previously experienced this alert on attachment by the Internet Mail provider and Mine is set to High so that would bump up the Heuristic checks and it alerted on the way out and on the way back in. You can disable this by setting the Internet Mail, Heuristics sensitivity to Custom, Customize button and uncheck the Attachment check (according to name), see image 2 and this gets past the problem you are experiencing of the attachment check by file name.