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Submitted By Zachary West (zacw)


Challenge/Response is an anti-spam plugin for Adium 1.3+. It works by hiding messages until the user answers a question you have picked. For example, "What is the square root of 49 in numerical form?" must be responded to with "7".

When the user responds correctly, all of the messages that were hidden are displayed as though C/R never did anything, and the user is added to the C/R whitelist so that they will never be asked again.

C/R works by displaying this prompt to unknown users, which are classified as:
  • Users not in your contact list (this excludes AIM's "recent buddies" group),
  • Users not in your C/R whitelist, and
  • Users you do not have a chat opened with
Since you set the challenge and response, the spam bots won't know what to say.

You can find the C/R preferences in the Adium menu, under Privacy Settings. You must enable C/R and set the challenge and response before it will do anything. If you disable C/R, it will display all the saved messages from users who have not yet answered the question while Adium has been running.

You can optionally log all messages which were hidden by C/R to a group chat called ChallengeResponse (one is created per account, a limitation imposed by the logger plugin currently). You can also hide all messages from blocked users, for protocols like MSN where blocked users can still message you.

The source is available from the Adium Mercurial repository at

Todo List:
  • Enable on selective accounts.
  • Hide authorization events until after a C/R.
Known Bugs:
  • With MSN, you will sometimes see the "switchboard error" message displayed in the chat window. This is caused by the bot not properly responding to received messages. A future version will prevent their display.
  • This does not interact well with "Open chats when typing begins" (psychic option in Advanced>Status) as it will open a chat and auto-whitelist the user. This may not be a problem for spam, depending on if the spammers send typing notifications.


  • Fixed adding to whitelist when the whitelist is empty.
  • Logging of messages to an imaginary group chat, for quick review of possible missed messages.
  • Add users to the whitelist from the Whitelist preferences.
  • Hide messages from blocked users.
r25553 - Initial release.


You can reply to individual comments by clicking the "Reply" link next to each.

# by dcentity2000 on 11/10/08 at 13:02:36

Now THIS is smart

# by jhonbob3 on 11/10/08 at 13:34:00

Wow. If only I had spam bots IMing me all the time this would be awesome. Alas I don't.

# by slacker on 11/11/08 at 09:28:26

There is a problem if spammers send spam via authorization request ...

# by zacw on 11/11/08 at 09:51:50

I've added this to the TODO list.

# by slacker on 11/11/08 at 09:54:13

thx :)

# by shiroineko on 11/14/08 at 00:48:19

Plus button on the whitelist tab doesn't seem to work.

# by zacw on 11/14/08 at 07:18:33

Strange. I've uploaded a new build (with no changes…) that fixes this. Must have been a weird build.

# by shiroineko on 11/14/08 at 11:55:36

Strange, but it still doesn't work. Is there any way to get some sort of debugging output?

# by zacw on 11/14/08 at 12:08:32

Open /Applications/Utilities/, it should be logging there.

# by zacw on 11/14/08 at 12:20:51

Oh, *facepalm* I see why. If your whitelist has no entries, it won't be able to do the add. I'll fix this sometime today and upload a new copy. For now, you can add without problems as long as your whitelist has at least one entry.

# by zacw on 11/16/08 at 12:31:43

I've posted an updated build which fixes this.

# by shiroineko on 11/16/08 at 14:47:52

Looks to be working ok now. Thanks!

# by BlueRevolution on 03/18/10 at 03:16:12

The problem seems to have reoccurred with Adium 1.4b17. The + button yields an entry labelled "(placeholder)", but as soon as I edit the text or try to change the protocol, it disappears again.

# by macjeep on 06/08/09 at 00:43:34

Mac OS X 10.5.7, Adium 1.3.4, I can't add any contacts to the Whitelist with the plus sign button. An AIM logo and (placeholder) appears, but when i go to change it, the entry disappears. Also, should be an option to automatically add all contacts in my contact list.

# by savrus on 11/18/08 at 04:20:16

Thank you for your work. I can't get the source code from svn:

$ svn co svn:// .
svn: No repository found in 'svn://'

# by zacw on 11/18/08 at 07:19:31

Whoops, sorry, that /svn is extra. svn:// should work.

# by savrus on 11/18/08 at 07:54:10

It works, thanks!

# by cguyer on 11/18/08 at 11:58:15

whitelist clears when trying to add someone, even when there is at least 1 entry already in it.

# by ChamY on 11/18/08 at 22:38:23

Doesn't work for me.
The Whitelist didn't work (I can't add entries), and I receive always spam (But I don't receive the bot message. I have this in a bot spam chat window : "Impossible to send message. A standardist server error".

# by dchoby98 on 11/19/08 at 11:54:05

Hi Zac -- excellent idea, but I've found a slight flaw. :) Most of the MSN spam I get involves a bot sending me a message and immediately signing off again -- so when the plug-in tries to send the challenge, the message bounces, and a window opens with the error "Could not send message...". I think that, if possible, it would be sensible to keep that message window from opening. Is that possible?

# by zacw on 11/19/08 at 12:10:31

Yes, though it might take some additional hacking. I don't think the "Can not send..." messages are content objects, so it might be difficult to hook into and prevent it from displaying. I'll check it out.

# by ATMB on 11/22/08 at 06:07:47

This is something WONDERFUL and USEFUL... needed since the big yahoo messenger spam we get...

Yahoo Messenger for Mac has the option to "Ignore messages from users not in contact list"... we can just have this implemented... ;)

# by hackand on 12/05/08 at 12:42:40

You can do that in Adium, actually. Go to the Adium menu, select "Privacy settings…" and configure it as you like :)

That's how I fixed my big MSN spam issue.

# by Davrim on 12/17/08 at 11:59:36

Is it possible to enable this for specific people ON my contact list? I've got a math-loving friend who would probably get a kick out of having to solve a math problem to IM me.

# by Contivity on 01/12/09 at 14:30:00

I actually think turning this on for specific people also helps if you know one of your buddies are infected with virus that randomly sends spam, or the account is hacked and it randomly sends spam. So, their message is only displayed if and only if they respond to the challenge. I don't usually get random spam, but it's more of a few buddies that isn't aware they're infected.

# by dinavil on 01/12/09 at 20:04:24

I agree, i would like to see a blacklist instead of a whitelist since i have more healthy friends than infected friends. Actually I want this plugin to use in 3 friends of mine, because I know they are infected, it would be stupid to whitelist everyone but them, I dont think I'm the only one with more healthy friends than infected ones, hope you can do this Zacw ;)

# by dcvandiver on 12/26/08 at 07:14:08

This is great.

# by The-Kenny on 01/14/09 at 12:50:12

I've added a small setting which makes it possible to choose if the response of the possible spammer just has to contain the configured response. My changes are in a git-repository at

I hope I'm allowed to make this changes.

A patch is ready if you want to merge this into your SVN-Repository. Just contact me.
(There is a small code-duplication, but this isn't a big issue...)

# by dharris on 02/26/09 at 16:38:26

After I updated to Adium 1.3.3, I was prompted to disable challenge/response. I did but now I can't figure out how to re-enable it.

Any help?

# by abfa00 on 03/29/09 at 20:53:51

THANK YOU- I've been getting a *lot* of AIM spam lately and am incredibly glad to have found this.

# by durandal on 04/12/09 at 17:48:59

Is there any place for a simple text filter to be added to this plugin?

It may fall outside your set of planned features, but rather than a challenge/response, I'd much rather filter incoming messages from people not on my contact list for content. MSN spam is generally repetitive for about a week, and I wouldn't mind managing the filters by hand.



# by uwzero on 07/26/09 at 19:27:52

Any word on MSN's switchboard error??

# by Clint5047 on 08/25/09 at 23:26:52

I was wondering if it was possible to make a setting where you can exclude certain services. For example: I really need this plugin on MSN, but I don't like it on Facebook chat.


# by GeforceFX on 10/22/09 at 18:30:36

Sehr gute idee!
vll etwas mehr einstellmöglichkeiten, aber trotzdme topp!

# by hodok on 01/05/10 at 08:51:35

That's a pity, i need spam filter only for authorizations requests in ICQ, nowhere else i got even one junk message

# by saintraze on 04/01/10 at 23:13:18

Like others mentioned in earlier versions, the version I downloaded today, 4/1/10, does not allow me to enter names in the whitelist. When I type a name in, the list clears, as mentioned above. I am on a Mac running 10.5.8.

# by saintraze on 04/01/10 at 23:14:14

Has this not been solved? Or am I missing the information that would allow me to add names to the WL?

# by Foky on 01/10/11 at 04:05:19

Are you still working on this?

# by johannes_simon on 02/13/11 at 12:53:47

Hey there! Please do implement this filter for authorization requests as well, 99% of the SPAM I get is through authorization requests (and from ICQ, like for most others apparently). I wish I could just cancel my ICQ account, but that's no option for me as most of my contacts use ICQ.

# by batzel on 07/02/11 at 13:29:36

I'd love to be able to have multiple acceptable answers for this -- for instance, "Where do I work?" --> Company Name or CompanyName or CN or DepartmentName

On the whole, this looks great! Thanks much.

# by batzel on 07/02/11 at 13:47:47

Oh, and yes I know I could rewrite the question to make it have only one specific answer. That was just an example. I'm just trying to make it easier for people while making it harder for bots.

# by smajor on 09/14/11 at 01:24:04

Does anyone know if this is still being developed? It's not working with the latest Adium, bots are getting through...

# by HenkPoley on 10/31/11 at 11:48:55

I now get the error "This plugin does not support your native architecture", with the option to disable it. Which probably means this plugin never worked on Intel when not forcing Adium to run under Rosetta.

# by unrealnighthawk on 03/26/12 at 22:49:09

This plugin doesn't seem to work with the latest version of Adium 1.5. It was automatically disabled after it notified me that it was not compatible. Any chance we could get some support for upgrading this? I still get a ton of spam on one of my accounts and this is the only thing keeping me sane. :-)

# by gcat on 10/02/12 at 13:57:23

this plugin no longer be supported?
i gets a tonn of spam messages and dont'n have any chances to filter it (if i using adium)
what to do? =(((((

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