Outlook 2013 Users whose Mail applet stopped working in June 2016, see Outlook 2013: Control Panel Mail Won't Open .
We're seeing reports that Outlook won't open, returning a (basically useless!) error message that Outlook won't open. Attempting to open the Mail applet in the Control panel results in an error message that Outlook is out of memory or system resources.
"You need more memory or system resources. Please close some Windows and try again."
To get Outlook back into working mode, open the registry editor and delete or rename the windows messaging subsystem key. We don't know why the key is corrupt, but this seems to fix the problem and doesn't take as much effort as completely removing Office and reinstalling.
Renaming this key means you will lose your profile and will need to recreate it. There really is no way to avoid this. Sorry.
Outlook 2010 and older:
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem
Edit the Registry
- Press Windows key + R to open the Run command.
- Type regedit in the Open field and click OK.
- Locate the key then right click on it and choose Rename.
- Type OLD at the end of the name.
- Try opening the Mail applet to create a new profile.
If Outlook works, you can delete the renamed key.