10.4.7 and Mail Attachment problem

Question

The 10.4.7 update has caused major problems for me, on several different Macs. When I send an email to a Windows user, they tell me that the attachment didn´t come through.
I had this problem with some Outlook users before, but now it seems to affect everybody. I found similar problems on a couple of other Mac-forums.

Answer 1

I just recieved an email from F-Secure, after I told them, that no attachments sent from Mail (after 10.4.7) go through to F-Secure / Windows users.
They have investigated the problem and reported this:
The attachments MIME header has the following fields: name and filename.
For some reason Mail removes the blank spaces from the name field but leaves the filename field untouched. These differences in the fields make F-Secure remove the attachment (alarm).
One "fix" is removing the blank spaces from the filename, for example File 1.pdf >> File1.pdf. But this in not easy computing. Everything works just fine with 10.4.6 and before, but 10.4.7 >> is causing the problems.
PowerMac Dual Core G5/2,3GHz | 250Gb | SD | 23 Cinema • PB G4/1,67GHz | 15,2 | 8   Mac OS X (10.4.7)   AppleFarmer