Opened on 04/22/2014 at 11:45:55 AM

Closed on 08/29/2014 at 09:06:31 PM

Last modified on 08/29/2014 at 09:59:52 PM

#369 closed defect (incomplete)

Adblock adds a huge load of CSS to Office365 Outlook mails

Reported by: TomNaessens Assignee: sebastian
Priority: P2 Milestone:
Module: Platform Keywords:
Cc: mapx, greiner, fhd, philll Blocked By:
Blocking: Platform: Chrome
Ready: yes Confidential: no
Tester: Verified working: no
Review URL(s):



I'm working on Safari 7.0.3 on a Mavericks Macbook Air. On this machine, I use the webmail from Office365, located on

How to reproduce

  1. Send an email from this platform to e.g. a gmail account
  2. Look at the source of the received email

Observed behaviour

This is the source of my received email: As you can see, there are over 3000 lines of CSS code added by Adblock. When disabling this adblock on that page, the mail is clean.

Expected behaviour

I expected that Adblock would not add CSS to my sent emails.

Attachments (0)

Change History (16)

comment:1 Changed on 04/22/2014 at 12:45:32 PM by mapx

which ABP version are you using ?
what filter lists are enabled ?

comment:2 Changed on 04/22/2014 at 12:45:47 PM by mapx

  • Cc added

comment:3 Changed on 04/22/2014 at 12:52:40 PM by TomNaessens

Only EasyList is enabled. Version No idea if this helps but the other AdBlock also has this issue.

comment:4 Changed on 04/22/2014 at 01:56:03 PM by mapx

  • Priority changed from Unknown to P2

comment:5 Changed on 04/22/2014 at 03:17:38 PM by philll

  • Resolution set to duplicate
  • Status changed from new to closed

Probably a dublicate of #264

comment:6 Changed on 04/22/2014 at 03:23:48 PM by mapx

I don't think is something like #264

There was a bug in the ABP for chrome apparently fixed. See:

#369 is reported for safari, #264 is for IE (don't share such much code)

Last edited on 04/22/2014 at 03:27:48 PM by mapx

comment:7 Changed on 04/22/2014 at 03:25:22 PM by mapx

  • Resolution duplicate deleted
  • Status changed from closed to reopened

comment:8 Changed on 04/23/2014 at 12:58:28 PM by sebastian

  • Owner set to sebastian
  • Status changed from reopened to assigned

comment:9 Changed on 04/23/2014 at 02:33:22 PM by sebastian

  • Resolution set to worksforme
  • Status changed from assigned to closed

I can't reproduce. We use .sheet.addRule() that the CSS we inject, don't show up in cases like that.

Are you sure that you are using Adblock Plus and that it is your only adblocking extension?

Last edited on 04/23/2014 at 02:42:45 PM by sebastian

comment:10 Changed on 08/08/2014 at 06:28:08 AM by mapx

  • Cc mapx added; removed
  • Component changed from Core to Platform
  • Platform set to Chrome
  • Resolution worksforme deleted
  • Status changed from closed to reopened

another user report the same behaviour but only in OSX ! in windows 7 it's all ok for him


comment:11 Changed on 08/08/2014 at 06:28:58 AM by mapx

  • Cc greiner added

comment:12 Changed on 08/27/2014 at 05:38:49 PM by sebastian

  • Cc fhd philll added

Back then I could sign up for a trial account without even providing payment information. However, now you need to pay at least 9.99 USD per month for Office 365.

But given how we inject our CSS, how few users have reported that issue, and that I couldn't reproduce it back then, I think it is rather unlikely that Adblock Plus is causing that behavior.

@fhd, philll: However, I wouldn't mind looking into that issue again, if you can get us an Office 365 account for testing. If you think this isn't worth the hassle, feel free to close the issue again.

Last edited on 08/27/2014 at 05:40:19 PM by sebastian

comment:13 Changed on 08/28/2014 at 06:58:33 AM by fhd

You've got a subscription now Sebastian - this does look like something we want to fix if we can.

Last edited on 08/28/2014 at 06:59:24 AM by fhd

comment:14 Changed on 08/29/2014 at 07:02:50 PM by Bezoar

I've been seeing this in Chrome for at least the last two days; a customer blocked my email address because of a spam link ( in the enclosed CSS at the pastebin link above. I unblocked Office365 to work around this for the time being, but since I can't (yet) get my employer to move off of Office365, I'll gladly try out any fix that may be forthcoming.

Chrome 37.0.2062.94
OS X 10.9.4
MacBook Pro 2011

Last edited on 08/29/2014 at 07:06:57 PM by Bezoar

comment:15 Changed on 08/29/2014 at 07:11:45 PM by sebastian

  • Ready set

I finally can reproduce the issue. As workaround until it is fixed, you can just whitelist (click ABP icon, toggle "Enabled on this site", reload page).

Last edited on 08/29/2014 at 07:12:49 PM by sebastian

comment:16 Changed on 08/29/2014 at 09:06:31 PM by sebastian

  • Resolution set to invalid
  • Status changed from reopened to closed

Apparently the stylesheet is injected into the light DOM again on Chrome, exposing it to the website's JavaScript. However, #1290 will fix this issue for recent versions of Chrome.

We are still using .sheet.insertRule() to avoid mess like that, regardless of Shadow DOM. But for some reason Outlook 365 serializes our style element, which is pretty silly on their end.

However, there is nothing we can do here to fix this issue for browsers that don't support Shadow DOM. So I close this issue as invalid. However, you can still whitelist Outlook 365, if necessary.

Last edited on 08/29/2014 at 09:59:52 PM by sebastian

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