I travel a lot to the USA and use my laptop daily.
In my case the two points are important. Firstly, your laptop will work in any country on their relative power (for the USA 110v). However you will need the correct plug conversion to plug into the local power. The converters are available in all UK electrical shops. In the States convert the 3 pin plug to a 2 pin plug. The existing transformer on the laptop power lead will recognise the strength of the power and adjust accordingly.
However, to go online, you have to use a local server to where you are and then, once on line, you can surf the web under their service and collect your emails by going into your UK servers home page, finding members services, typing in your username and password.
Hopefully ths advice makes sense for you