When the Outlook Social Connector is active, it will create {GUID}.html file in your Temporary Internet Files.
These files then show up in your Internet Explorer History.

If you don't want the .html files to be created and you don't need the Social Connector, you can disable the add in

Sources:
Rational Expectations - Outlook 2010 + Social Connector + Security Zones
Microsoft Answers - When I open Outlook 2010,or hit send/ receive, a blank tab opens in Firefox.
Microsoft Answers - outlook 2010 Social Connector causes html temp file pop up
Office > Microsoft Office Forums > Outlook IT Pro Discussions > Outlook Connector and News Feed folders
Experts Exchange - Outlook 2010 creates temp files that appear in the IE Favorites History

Scenario:
An Outlook 2010 SP2 client within an Exchange Server 2010 or 2013 environment.

After installing updates after Februari 2015 (specifically KB2956128) whenever you try to search a shared mailbox (or contact list) you get the error:“The operation failed. An object could not be found”. The Outlook version after the KB2956128 update is 14.0.7143.5000.

Workaround:
Uninstall KB2956128.

Source: OL2010:Search Problems after install KB2956128

There is no GPO setting for Outlook 2010 to disable all access/use of MailTips in Outlook 2010.

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail]
"DisableMailTips"=dword:00000001

Source: Exchange TechCenter Forum - Disable MailTips query in Outlook 2010 completely

When color categories for a shared mailbox do not always show all categories in a Remote Desktop Server environment it can be necessary to delete the cache files:

1. Close Outlook.
2. Go to %localappdata%\Microsoft\Outlook\RoamCache\.
3. Delete all Stream_CategoryList_*.dat files.
4. Start Outlook.