Should I empty my junk folder?

Be sure to empty your junk folder at least every thirty (30) days. If you find a message that is clearly not relevant, you can highlight it and click Junk. The mail is moved to your Junk folder. Sometimes messages may be put in the Junk folder that are not really junk mail.

Where is the junk folder on Android?

Bring up your Folder List – on my phone it’s the Menu button, then Folder List. While viewing the Folder List, find the Junk Email folder, and long press it.