The wifi will work just fine. There will be no charge for accessing your email from across the pond the only fee could potentially be for wifi access. The few trips I have taken to Europe I found some of the hotels charge for Internet access. Your charger that came with your iPad accepts 110-220 volts (220 is used in Europe ). All you will need is an plug adaptor for your charger and you will be good to go. You can buy the appropriate plug adaptor at any electronics store for a few $. Don't let them talk you into a transformer to change the voltage unless you will be bringing other plug in items that don't accept 220v.
One thing to be careful of is if you have a cell phone turn it off or put it into airplane mode and just turn on the wifi. Data roaming from Europe could easily cost you more that the plane tickets.
Have a good trip.
Mike