Things I Did Not Know - Periods and Plusses in Gmail Addresses

I often have to explain to folks that email addresses are not case sensitive.  But I confess I never knew this (applicable only to Gmail I think, other systems are different)

I recently discovered some little-known ways to use your Gmail address that can give you greater control over your inbox and save you some time and headache. When you choose a Gmail address, you actually get more than just "" Here are two different ways you can modify your Gmail address and still get your mail:

  • Append a plus ("+") sign and any combination of words or numbers after your email address. For example, if your name was, you could send mail to or
  • Insert one or several dots (".") anywhere in your email address. Gmail doesn't recognize periods as characters in addresses -- we just ignore them. For example, you could tell people your address was, or (We understand that there has been some confusion about this in the past, but to settle it once and for all, you can indeed receive mail at all the variations with dots.)

For me, the real value in being able to manipulate your email address is that it makes it really easy to filter on those variants. For example you could use when you sign up for online banking and then set up a filter to automatically star, archive or label emails addressed to hikingfan+bank. You can also use this when you register for a service and think they might share your information. For example, I added "+donation" when I gave money to a political organization once, and now when I see emails from other groups to that address, I know how they got it. Solution: filtered to auto-delete.



  1. Hal_10000:

    I've done this with my personal e-mail server. Side benefit: it lets you know who is selling your e-mail address.

  2. El Baconcabra:

    That's an awesome tip -- thanks Warren! That'll make software testing a lot easier for me.

  3. ErikTheRed:

    We've had something similar custom-baked into our email system for years. I've always found it interesting to see who shares your email address and who doesn't.

  4. james:

    No doubt everyone here has had bank phishing scams.
    The solution is probably not to have expensive cyber security ware.
    Nearly everyone will have a few legacy accounts at banks with $0.05 in them, if not set them up.
    When the phishers come calling, give them the account details for "legacy account at crap bank I don't use anymore" and allow them to spend time pirating your account at less than minimum wage.
    Also, when they phone you (Indian / Nigerian guy pretending to be from microsoft) keep them on the phone as long as possible. Make a cup of tea, take the dog for a walk, say you're having a problem with your ISP...

    Also saves on training staff.

  5. Steve:

    This also works if you have Google Apps (or whatever they're calling it now), and are using Gmail with a custom domain (I do). You are also username {Shift-2} There was some trademark dispute somewhere in Europe and they couldn't use there. I've received some emails like that. Though I have a very common name, so I get lots of emails because people enter their address wrong.

  6. Jay Solo:

    The dot thing has been horrible. They allowed people back when to sign up for fname.lname as completely distinct accounts from fnamelname. My wife signed up for a dotted one. She gets e-mail for people who are undotted. I have one that is undotted. I get e-mail not only for people who are dotted, but also for people who have given out their address as the undotted version, And it's been a whole string of different people! I've unsubscribed my address from a lot of e-mail lists over the years. The wife's most recent one was a prospective employer e-mailing not-her, and that was using the dotted version. She took pity and e-mailed back to explain they had the wrong address. Having run a mail server for a law firm, the inability to consider dotted and undotted e-mail names distinctive on the part of a company like Google just blows my mind.

  7. craftman:

    Another benefit is you can sign up for 2 different accounts on the same website. For instance I have a need for two distinct Shutterfly accounts, one is "myemail" All the email (order tracking, receipts) comes to my personal address, I don't have to have one account signed up as my work address or something. Website login names, if they allow email addresses, consider them two distinct usernames.

  8. Don:

    Another useful thing is, when you sign up for something you think might wind up being spammy (e.g. a newsletter), put "+newsletterfoo" or something in the email. Then, if a spammer sends you spam with that address, you know who the culprit is, you can block the email and file a complaint with the service.

    After spending 15+ years running ISPs, I now simply assume that everyone I do business with will eventually sell my email address, so I have hundreds of these out there floating around the interwebs. I actually do it a little differently because I'm using a google domain, but still it's the same basic function.

  9. Michael Stack:

    I've been using this feature for years (+$NAME_OF_COMPANY). The problem historically is that there are a lot of bad email validation routines in place, and email addresses with '+' signs get (wrongly) rejected when I try to use them. This has been improving the last few years, but I still run into it from time to time.