More about technology/electricity at Hogwarts

[acci0firebolt]

No: HPFGUIDX 32659

Our conversations about Dean and his soccer teams have reminded me of 
a point that I have wondered about for a while.  How, exactly, do 
Muggle-born witches and wizards keep in contact with their family 
while at Hogwarts?  And along those lines, how do the Dursleys manage 
to send Harry his 10 pence piece or whatever he gets for Christmas in 
SS/PS?  I would imagine that the Dursleys would not be too keen on 
using owls, and they wouldn't be up to relaying it through another 
wizarding family either ... ?
- Irene