in some countries such as Germany, GMAIL conflicts with local companies that have registered GMAIL trademarks before.
so GOOGLE can't use the GMAIL trademark and email service there.
so just use GOOGLEMAIL instead!
so, everyone's GMAIL is actually @GOOGLEMAIL.com and @ gmail.com.
if you have GMAIL, such as ABC@GMAIL.COM's email address, you can also tell others that your email address is from ABC@GOOGLEMAIL.COM.
Similarly, you can send yourself an email and send it to ABC@GOOGLEMAIL.COM, and then you and yourself will receive this email!