Created attachment 48061 [details]
Mail created by kmail

Version:           1.13.3
OS:                Linux

I attached  simple file with an enter in the filename in kmails composer and noticed that the resulting mails always have a complete destroyed mime attachment. I attach a test.mbox with such an email created by kmail and a test_enter.tar which has an example file included with an enter in its filename

Reproducible: Didn't try

Steps to Reproduce:
 1. open kmail
 2. press "new"
 3. attach file with enter in filename
 4. press message -> "save as draft" (send would also work, but this is easier for an local test)
 5. Go into your drafts folder
 6. open mail you send
 7. press right mouse on the attachment symbol
 8. click on "open with..."
 9. open it with kate

Actual Results:  
The file you attached now starts with something like:

%2Etxt
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
	filename*=us-ascii''test
%2Etxt

and after that there is the actual file data

Expected Results:  
Just get the file data without that scrambled mime header stuff