On most stock OSes, this will show your password to anyone who views the list of processes on the machine.
Try 'imapsync' [1] instead, as it uses a config file for your credentials instead of command-line arguments, keeping the secret(s) out of the process list.
Also, the author of this blog post is showing his inexperience:
> BaGoMa's output is pretty informative so I send it to log a file in case I ever want to check up on it and make sure the backups are still working.
You won't ever do that (no reason to check the logs when it's working), and it will fail (effectively-silently) one day without you noticing, and then you won't have backups when you actually find that you need them. Don't do it that way.
Instead, use a cronjob wrapper script (e.g. [2]) that is silent on success and outputs on error, so the "cronjob-output-as-email" feature works to notify you when it breaks.
[1] http://imapsync.lamiral.info/
[2] https://github.com/sneak/misc/blob/master/cronify/cronify