Brits that signed up for the service, which launched in April 2004, after October 2005 were given @googlemail.com addresses due to a legal battle between the search engine and Independent International Investment Research, which had its own webmail application called Gmail.
Google hasn't revealed what happened in the legal battle.
However, in a blog the search engine announced that anyone signing up to the service from this week will be given the Gmail suffix, which Google said uses 50 percent less characters.
The search engine estimated this saves approximately 60 million keystrokes a day.
"At about 217 microjoules per keystroke, that's about the energy of 20 bonbons saved every day!"
Google also said web users that already have a googlemail email address will soon have the option to switch to the matching @gmail.com or retain @googlemail.com.
See also: Google invests in online payment firm