Automatic disposable email addresses for Google Apps

Plus Suffixing

There’s a pretty nifty feature with gmail that most people don’t know about. I’ve seen people reference it as the “plus hack” or “plus suffixing”. If you have example@gmail.com, you can add a “+” followed by any letters and numbers, and it will still be delivered to example@gmail.com.

I’ve been using this for corporate email forms — if facebook wants an email, they get matthew+facebook, for example. I can then add a precise filter on that “To:” address and delete all email from that company if it “goes evil.”

There’s a glitch in plus suffixing, though — most web forms don’t realize that the plus sign is a totally valid email character, and will reject your plus-suffixed hack.

So what to do?

Well, if you’re using gmail, you’re out of luck. But if you’re using a google apps account for a custom domain (say, your company or family), and you are an administrator for that domain, you can enable “minus suffixing”!

Router bot to the rescue

Note that you must be an administrator of your google apps account to make this work.

Log into your google apps dashboard. If you’re in your email account, there will be a “Manage this domain” link that will take you to the dashboard.

Picture 8First create a “router bot” account.

  1. Click “Users and Groups
  2. Click “Create a new user
  3. Enter “Router” for first name,
  4. “Bot” for last name
  5. “router” for the username
  6. Copy the temporary password for later
  7. Click the “create new user” button
    Picture 11

Tell “Catch-all” to use the router bot.

  1. Click “Service Settings” then “Email
  2. In the “Catch-all address” section, choose “Forward the email to:” and enter “router
  3. Click “Save changes” at the bottom of the page

Configure the router bot

  1. Log into the “router” account’s email
  2. Click “Settings
  3. Click “Filters
  4. Then for each user you want to enable routing for, do these steps:
    1. Let’s say the username is bob
    2. Click “Create a new filter
    3. For the user you want to enable routing for, enter the username (“bob”) , followed by a dash (“-”), in the “To:” column
    4. Click “next step
    5. Check “Forward it to:” and enter the user’s full email address (like “bob@domain.com”)
    6. Check “Delete it” as well.
    7. Click “Create Filter

Test it out

Sending an email to “bob-test@example.com” should be delivered to “bob@example.com”.

“Dot-suffixing” (bob.test@example.com) should automatically get delivered to bob@example.com). If google changes this routing implementation detail, though, just add another filter to the routerbot that looks for “To: bob.” and forwards to bob.

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Posted in Technical HOWTOs
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  • Helen

    Matthew … I followed the link in your 10/29/09 post on lifehacker. This solution for multiple addresses is BRILLIANT! Thanks very much.

  • http://twitter.com/3rdparty Josh

    Excellent idea and guide – great workaround for many sites not accepting “plus addressing”

    It might be a good idea to enable the “Never send to SPAM” setting when creating each filter in the router account – that way spam filtering (hopefully) will be done in the end users Gmail account, and won’t sit in the Router SPAM folder.

  • Steven Schoch

    Genius! I found this page from your posting in the Google Postini services help forum on 08/29/09.

  • http://x3ja.co.uk/ x3ja

    Great post.

    Might be worth creating another filter to delete everything else that comes in… I get quite a few spam to random_username_guess@mydomain.com … not that you’re going to run out of Gmail storage anytime though.

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  • http://chastity.com google filtering is lame

    uhh that’s not disposable: it in NO way whatsoever protects the underlying address from mining/acquisition

    yahoo, however, is the only large free email provider to offer free DEA: AddressGuard

    SW

  • http://matthew.mceachen.us matthew

    It’s proven to be pretty reliable — I’ve been using this for several years now, and it seems like no-one is doing dash-trimming from emails to get “better” email addresses.

    I agree with you, though — humans could probably intuit what your “real” email address is just by looking at the string. The point is, you’re not dealing with humans. You’re dealing with computers.

  • D B

    This is intriguing, but still it does little to protect you, as your true email behind the disposable address is instantly obvious.

  • Anonymous

    I agree that it’s obvious to a human — but you’re worried about the bots, not the humans, here.

    Also, is “foo+bar+baz@domain.com” obviously going to user “foo”?

  • http://red66.com Carlos Granier-Phelps

    Genius… Thanks for the idea.

  • Anon

    The bot’s filter doesn’t have to forward bob-test@example.com to bob@example.com, it could forward to john@example.com.  The true email address behind the disposable addresses doesn’t have to be obvious even to a human.

  • Guest

    Still works. I had to setup forwarding first, but you can leave it disabled.

  • Dan

    Can’t believe I only just found this. Thanks so much! I was running out of sites that supported ‘+’ throwaways.