Accidentally I noticed a serious problem with Gmail. I sent a mail to my Gmail account from my official mail id while checking the mail forwarding feature. My Gmail id looks like firstnamelastname@gmail.com. But my mistake I put a dot between my firstname and lastname. So I sent the mail to firstname.lastname@gmail.com and there is no such id as far as I know. Surprisingly the mail got delivered to firstnamelastname@gmail.com. I checked it 2,3 times and confirmed that it really works. Gmail automatically forward firstname.lastname@gmail.com to firstnamelastname@gmail.com since the former id does not exist or it assumes something else. But when I try to login to either gmail or gtalk using firstname.lastname@gmail.com, it complains that there is no such user. But only mail sent to this id works fine. Is it a feature or a design flaw? What happens if suppose there are two different persons, one having firstnamelastname@gmail.com and another with firstname.secondname@gmail.com? The mail sent to one guy will be forwarded to the other guy. I could not check if Gmail has any mechanism that prevents two users with same first and lastname to have two different mail ids but only with a dot difference. But if Gmail thinks it is a feature, it gives to its users, then they should also allow login to their services with and without a dot so that it eliminates redundant email creation and privacy issues.
When I carefully examined the mail I received with a dot separating firstname and lastname, Gmail has explained how the email id is being read by Gmail. Gmail don't care about dot (.) in the gmail user name. Even if someone send a mail like f.i.r.s.t.n.a.m.e.last.name@gmail.com, it will work, it seems. But it won't allow the user to sign into his account like this