I have created a simple log file (abc.log) with Hello World, from my UNIX script. At the end of the script, I have attached the log to my email using uuencode & mailx command.
THe email was send successfully and opening on my desktop without any issues.
I have the email sync with my iPhone too. When I tried to open the same attachment (abc.log), it is opening and showing all junk data.
I made a try with BlackBerry 10 device, it is opening without any issues.
You would usually use uuencode in a pipe with other commands or on a file with a redirect. What I think you have done it to execute it by itself on the command line, which will read from STDIN (usually the keyboard) and display on STDOUT (usually the screen)
Something more like this might help:-
(echo Hello ; uuencode --base64 attach_this.csv attached.csv) | mail my_email@my_provider.org
It's not complete and probably doesn't do what you want, but it's an example of what you should be thinking of.