I have read and re-read the USPS rules on their website and still am not clear on this... I like to print the package label on paypal as media mail with dc. It would be very convenient to mail from home on a rural route.  Can I do this? Or do I just try it once...

Yes, you only have to hand the package to a postal worker if it's over 13 oz and you use stamps.  As long as you're using electronic postage you can send it out from your box.  Assuming your mail carrier will pick it up, some may not be equipped to do so, but if you're rural, they're probably reaching all the boxes from a car/truck  vs. hand carrying items.  The electronic postage is traceable, so it can be left out for them, vs. stamps, which are not.  It has to do with packages that could potentially contain dangerous items.

I do all the time.  anything over 13 oz  I rather go to the PO.  Mine is generally scanned within an d 1 or 2 hour of being picked up.  However that is rare..I think

Should work Miriam.  Just make sure the return address is a match for your mailbox, and the package is under 13 oz.  But don't expect a local scan unless you actually purchase postage at the counter, postal employees are discouraged from 'gratituous' scanning, since the only one required is the delivery scan.

The package doesn't have to be under 13 oz if you are using paypay or postage from this site. 

I do it all the time regardless of how much it weighs.  My mailman is great!

Just make sure your carrier will accept them.  My sister lives in the Philly burbs and her mail service is "delivery only," anything outgoing has to be dropped at a blue box or the postie.  Which is a bit of a pain, but they do have really awesome drive through windows...

I do it all the time using my rural mailbox in MIchigan.  My mail lady did say that she can't take anything that weighs over a pound though.  I'm not sure about the 13 oz rule. 

I had a package that I know did indeed weigh a pound.  I just happened to be at the mailbox when she drove up.  She took the package out of the mail box and hefted it.  She said this weighs just about a pound and I can't take it - 9/11 rules.  She told me you can't drop a package that weighs that much in a blue box either, it must go to the PO.  The clerks at the PO have told me the same thing.

A one book package - not a problem at all.  Actually anything under 13 oz that'll fit in your mailbox. 

Personally I like using PBS/DC.  You get an instant credit and if it does go lost thanks to Meghan I know you still keep your credit.  (Thanks again, Meghan.)