I've used four different email accounts (Gmail, GMX, Hotmail, Yahoo) & two email clients (Apple's Mail, Thunderbird) to email blog posts to Google's blogger. Each email is correctly sent to Blogger as a draft; however, the attached images are being renamed.
If I attach a image named 1_w.jpg Blogger appears to append a randomly generated number to the end of the original file name such as 1_w56984564.jpg. I am only using 0-9, a-z, - (hypen), and _ (underline) in the files names.
I have a script in my XHTML template which automatically inserts each image's file name as the image's caption within a post thus I don't want the file names changed as these are used for cross-reference by readers.
If I instead send the same email to one of the my other email accounts the attachments are not being renamed. If I upload images to Blogger via Blogger's own editor they are not renamed.
It would appear that this issue is on Google's. I could not find anything via extensive Google searches and on Blogger's own forum in regards to a solution.