More receive addresses with electrum
There's no Expert Mode anymore. The Gap Limit has been hidden from the UI as it was unnecessarily complicated for normal users, and it is not a good method for merchants.

If you need to change the gap limit, enter this in the Console tab and restart the client (Tested with Electrum 3.0):

wallet.change_gap_limit(10)
wallet.storage.write()

To view/verify the current gap limit, type the follwing in the console:
wallet.gap_limit