- search for "older:2017/04/01"
- select UNREAD (via checkbox under search box)
- In the very first line, just above your emails, this line will appear : "All 50 conversations on this page are selected. Select all conversations that match this search"
- click "Select all conversations that match this search" (everything is now selected)
- click "delete" (ONLY if you're sure!!)

_________________________
Riocar 80gig S/N : 010101580 red
Riocar 80gig (010102106) - backup