When Microsoft Outlook start up time is slow first thing which we usually check is which add-ins are installed and whether disabling any of them improves situation. But even if you isolated one particular add-in which adds significant delays (normally Outlook add-ins load in few seconds) it is not necessarily means that this add-in can be sole cause of slowness. For example if your iManage FileSite / EMM add-ins are slow to start there is some additional things worthwhile checking.
If since your Outlook profile was created some changes have taken place on Exchange side (servers were added/removed, your mailbox migrated to new server during upgrade of your Exchange infrastructure etc.) it may contain references to old/non-existent servers to which your Outlook are trying to connect until exceeding some time-out limit and this could be actual cause of slowness.
To check whether this is the case you should look at the following registry keys:
[HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlook Profile Name8fa3465791d2b746a2c7d11ca063b282]\n”001e660c”=”outlook.company.corp”
[HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlook Profile Name406169da1432914e8075fa26cbcdc53a]\n”001e660c”=”outlook.company.corp”
[HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlook Profile Name1e8559cf990bb44792093b0cdfca0186]\n”001e660c”=”outlook.company.corp”
[HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlook Profile Name13dbb0c8aa05101a9bb000aa002fc45a]\n”001e6602″=”outlook.company.corp”
[HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlook Profile Namedca740c8c042101ab4b908002b2fe182]\n”001f662a”=hex:6f,00,75,00,74,00,6c,00,6f,00,6f,00,6b,00,2e,00,63,00,63,00,73,\n00,2e,00,63,00,6f,00,72,00,70,00,00,00
The last key is a REG_BINARY of the server name (outlook.company.corp).
If you see old/non existent Exchange server as a value of aforementioned keys it’s worthwhile to create new profile which should pick up proper settings from Exchange (if you use exchange 2010 everywhere should be the same domain name of CAS). You may also add these changes directly by editing registry or set these keys with group policy.
Another possible culprit could be your firewall/proxy configuration (especially on x64 systems) – slow loading of add-ins could be because of inability to check some certificate revocation because of your firewall/proxy config.