When you create a
Gmail account, you actually get two email addresses – one is the regular
@gmail.com address while the second email address has @googlemail.com in the
domain.
That means if your
email address in Gmail is something like abc@gmail.com, all email messages that
are sent to abc@googlemail.com will also be delivered to your own Gmail
account.
So whenever you
will get any email to abc@googlemail.com it will get delivered to same account.
So you can use abc@googlemail.com as a personal address like giving to your
friends, relatives, using on personal visiting card, etc and abc@gmail.com you
can use it for public places like your blog, website, etc.
