[Plugin: W3 Total Cache] How to Set Leverage Browser Caching ?

It looks like all except one of the items listed without expiration dates are from other sites, which I assume you do not control, and therefore cannot set an expiration date on.

So, reducing number of those is really the only option. Review all the imgshack images…

It looks like others are set to one hour, specifically set to keep content fresh.

The last item is the minify cache item which looks to be set to a week.

//http://www.tollymp3z.com/wp-content/cache/minify/000000/M9AvLqnMSdUx1C8v0C1ITE_NSyzL1IcxdJOLiwE.css
(6 days 23 hours)

http://gtmetrix.com/reports/tollymp3z.com/kcd8o5MA