Tough to decide whether this is a feature or a shortcoming. Gmail has a special ability. It parses the "gmail user id", ignoring existence of any dots in it. But while registering user ids, new user id is sensitive for dots.
For instance: If I send a mail
But while loggin in onto gmail account [from browser, Client], user needs to use the same id that was used to register with Gmail.
Good thing:--------
Virtually I can have "n" number of unique Gmail IDs that I give out to send me mail on. And I can filter my incoming mail according to these IDs.
Just as an example, if suppose I register with Gmail and create an ID: ab1@gmail.com, all the mails that are sent by anybody to these addresses will come to me:
But while loggin in, I'll have to use ab1 as username.
Bad thing:--------
If someone already have registered with any of the ID other than ab1, that user will get the emails that are sent to recepient matching to the respective username.
so if some sends an email to ab.1@gmail.com, email will go to atleast 4 users [in case if all combinations exist],
Apart from only him getting mails sent to him by anybody, one copy will come to me and other users. Supposedly.
Sounds funny and violation of users privacy as also.
Lets verify this.