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March 16

+'s and .'s in gmail

Hello all,

I have recently discovered that inputting the . and + signs in my gmail email address will effectively create a new email, with all email being sent to it being redirected to my normal inbox.

For example, say my email is johndoe@gmail.com . Now say that I want to create an account on a website, but do not want to use my normal email. I input john.doe@gmail.com, and the website treats it as a new email, but all mail is redirected to johndoe@gmail.com . This also works if text is inputted after a + sign, for example, johndoe+jane@gmail.com would redirect all email to johndoe@gmail.com .

I'd like to know why exactly this occurs. Is this because of technical restrictions? Or perhaps it is a bug in gmail itself? Thank you very much for your answers on this matter. --81.178.75.46 (talk) 10:57, 16 March 2022 (UTC)[reply]

Google's help says "dots don't matter in Gmail addresses". This is a gmail-specific quirk. Email_address#Local-part discusses the plus sign, saying "some mail servers support wildcard recognition ... this can be useful for spam control". Card Zero (talk) 12:13, 16 March 2022 (UTC)[reply]

But INABIAF. Philvoids (talk) 13:33, 17 March 2022 (UTC)[reply]

The + sign is one of the nicest hidden tricks of email. Basically everything between + and @ is ignored. Often when I need to register for some sort of commercial site to order something for instance, I will register mygmail+commercialsitename@gmail.com . Then whenever that starts showing up in my spam folder, I know where it is coming from and what site never to use again ;)

Some email providers don't allow you to use addresses like these, and similarly some websites won't let you enter emails with this trick. But when it works for you, it can be handy indeed. —TheDJ (talk • contribs) 10:13, 18 March 2022 (UTC)[reply]

The nicest part of that trick is not to "never use the site again" (some sites you will only ever use once, some others you have no choice but to use even if they are spammy) but to be able to filter incoming traffic. Say you use the address myaddress+some_company@domain for some_company’s web registration form, and subsequently receive spam addressed there. You can set up a filter that discards, or moves into a dedicated spam folder, every email sent to that address; and this does not impair your enjoyment of other subaddresses such as myaddress+another_company@domain.

That feature is extremely powerful (not just for spam control), trivial to set up on the server side, and fairly easy to set on the user side (it’s not just hardcore coders who know how to set up email filters, and virtually all of those people can do a filter by addressee). I am annoyed that many online registration forms reject "+" as an invalid character for an email address, and dismayed that many email providers do not allow it (that’s the part where I wanted to point my finger at Microsoft Outlook but apparently they managed to do it in September 2020). Tigraan^{Click here for my talk page ("private" contact)} 14:47, 18 March 2022 (UTC)[reply]

Thank you to everyone for your help. Thank you especially to @Tigraan:. I did not know about this trick's possible usage as a spam filter, but will be using it from now on! 81.178.75.46 (talk) 09:31, 21 March 2022 (UTC)[reply]