A new client side feature which Microsoft has released in Exchange 2010 SP1 is the ability of Outlook 2010 to automatically map all mailboxes to which the logged in user has full access.
There by, on each mailbox that you have been granted Full Access, you will see it on your own personal mailbox.

In Order to disable automatic mapping:

1. Go to this user mailbox, right click on it and choose manage full mailbox access, then just remove your user from the full mailbox access page
2. You can use ADSIEDIT, and go this user properties, and under msExchDelegateListLink attribute, just remove the link to your user
3. You can use the following script for future mailbox permissions – this will add full mailbox access with no AutoMapping.
4. You can remove msExchDelegateListLink values from multiple users properties using ADModify.net

In order to find all users that have Full Mailbox Access on other users’ mailbox, run the following powershell:

Get-Mailbox -ResultSize Unlimited | Get-MailboxPermission | ? {($_.AccessRights -match "FullAccess") -and -not ($_.User -like "NT AUTHORITYSELF")} | ft Identity, User

Message header can provide us with valuable information that will allow better troubleshooting of mail flow problems

To view message header in Outlook 2010

1. Open message you want to inspect
2. Click on the small square expansion button of the message navigation screen.
   
3. You will receive message properties with internet mail headers
   

Every time you open Outlook 2007 you are prompted to enter your domain credentials ,even though you know you have saved it?

To solve it try that one:
Open the following path:
In Vista C:UsersYourUserNameAppDataRoamingMicrosoft
Once open you will see numerous folders including a “protect” folder.
Delete the “protect” folder
When you have deleted the protect folder, restart Outlook.
You will be requested to enter your password again, but it will be the last time.

If problem exist When working RPC over HTTPs

If you are working RPC over https you are using or basic, or NTLM authentication
you need to be sure you are working NTLM.
Now in order to ensure that outlook not uses any cached password we need to do the following.
Go to Control Panel>User Acounts
Press on Advanced Tab button
Click on Manage Passwords button
Review stored passwords , and if you see IP address of your mail server you should delete it.

Now we need to patch te registry

1. Click Start|Run
2. Type regedit and press enter
3. Go to HKLMSYSTEMCurrentControlSetControlLsa
4. Find lmcompatibilitylevel DWORD parameter
5. Double-click on it and change its value to 3

If “Remember my password” doesn’t work and you keep getting prompted:

1. Close your Outlook
2. Go to Start… Run and type control userpasswords2 and press OK c) click on the Advanced tab and press ‘Manage Passwords’
3. Find the entry for your mail server and click ‘Properties’
4. Erase the Server name and type in ‘S1′ or whatever the simple name of your global catalog server is (without the quotes)
5. leave the password blank and click OK
6. Start Outlook, enter your password and check off ‘Remember my password’ one last time. It should not prompt again.

When you start Microsoft Outlook 2000/2002, you may receive following error messages:

Your logon information was incorrect.
Check your username and domain, then type your password again.
The logon credentials supplied were incorrect.
Make sure your username and domain are correct, then type your password again.
CAUSE
This behavior occurs because registry may be missing one or more values in the following registry key:
HKEY_LOCAL_MACHINESOFTWAREMicrosoftRpcClientProtocols
The following values are the core required values for Windows XP or Windows 2000:
Name Type Data
(Default) REG_SZ (value not set)
ncacn_http REG_SZ Rpcrt4.dll
ncacn_ip_tcp REG_SZ Rpcrt4.dll
ncacn_np REG_SZ Rpcrt4.dll
ncacn_nb_tcp REG_SZ Rpcrt4.dll
ncadg_ip_udp REG_SZ Rpcrt4.dll

The following values are the core required values for Windows 98:
Name Type Data
(Default) REG_SZ (value not set)
ncacn_np REG_SZ Rpcltc1.dll
ncalrpc REG_SZ
ncadg_ip_udp REG_SZ Rpcltc3.dll
ncacn_http REG_SZ Rpcltccm.dll

The following values are the core required values for Windows NT 4.0:
Name Type Data
(Default) REG_SZ (value not set)
ncacn_np REG_SZ Rpcltc1.dll
ncalrpc REG_SZ
ncadg_ip_udp REG_SZ RpcLtCcm.dll
ncadg_ip_udp REG_SZ RpcLtCcm.dll
ncacn_nb_tcp REG_SZ RpcLtCcm.dll
ncacn_http REG_SZ RpcLtCcm.dll
Following the system’s protocol binding order, you receive a prompt for credentials on each missing value until a value that matches the next protocol in the binding order is reached.
RESOLUTION
Use one of the following methods to resolve this behavior.
Method 1
Import a valid registry key from a computer that is working correctly. To do this:
1. Start Registry Editor (Regedt32.exe).
2. Locate and then click the following key in the registry:
KEY_LOCAL_MACHINESOFTWAREMicrosoftRpcClientProtocols
3. Click the ClientProtocols key.
4. On the File menu, click Export.
5. Save the file with a .reg or a .txt extension in the event you need to send the file by using Outlook. You must save and rename the attachment to a .reg extension to import the key.
6. Quit Registry Editor.
7. Rename the file that you just exported from a .txt file extension to a .reg extension, and then copy it to a folder on your computer.
8. Start Registry Editor (Regedt32.exe).
9. Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINESOFTWAREMicrosoftRpcClientProtocols
10. Select the ClientProtocols folder, click File, and then click Import.
11. Select the .reg file that you saved, and then click Open.
12. Quit Registry Editor.
13. Quit and then restart Outlook 2002.
Method 2
Use Registry Editor to manually create the missing values. To do this:
1. Start Registry Editor (Regedt32.exe).
2. Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINESOFTWAREMicrosoftRpcClientProtocols
3. Click Edit, click New, and then click String Value.
4. Edit the new string value with the name and data information that is in the table in the “Cause” section of this article.
5. Repeat steps 3 and 4 for each missing value.
6. Quit Registry Editor.
The information in this article applies to:
• Microsoft Outlook 2002 (Outlook XP)
• Microsoft Outlook 2000
• Microsoft Exchange 2000 Server
• Microsoft Exchange Server 5.5

It is a common task in corporate environment

1. You need to open a user with new meeting room name
2. Open new user’s mailbox
3. Go to tools> Options >Calendar options>Resource schedule
4. Mark the sections bellow

That is .

NOTE: In Exchange 2007 there is ability to create resources (Not Users) You can also set the resource capacity now! Eg: in one of your meeting room, only be able to fit 10 people, you can type in resource information, under the property of the object.

Show received meetings as tentative:

Meetings are automatically placed on the calendar as tentative, so that timeslots will not be overbooked. As meeting updates come in, prior updates are marked “out of date” and are automatically deleted. This means that meeting updates are not accepted in an out of order fashion keeping your calendar items current.”
You can stop/start the automatic addition of a tentative meeting when meeting request e-mail is received in Outlook by clearing/marking the check box for “Process requests and responses on arrival” :

1. On the Tools menu, click Options.
2. Click Email Options.
3. Click Tracking Options.
4. Click to clear/mark the “Process requests and responses on arrival” check box.

On errors:

Mapi session “/o=COMPANY/ou=Europe/cn=Recipients/cn=User1? exceeded the maximum of 32 objects of type “session”.

Task “Microsoft Exchange Server” reported error (0×80040115): “The
connection to the Microsoft Exchange Server is unavailable. Outlook must be
online or connected to complete this action.”

Task ‘Microsoft Exchange Server’ reported error (0×8004011d): ‘The server is
not available. Contact your administrator if this condition persists.’

Don’t waste your time on profile recreation … It doesn’t help!!!

Things to check .

1.      Ping to exchange server by short name and FQDN

a. If no ping check connectivity and name resolution.

b. Consider adding exchange name/ip to hosts file

2.      Go to file and check if “Work Offline” is not checked

a. If it is uncheck it.

3.      If you have check point client try to

a. Disable security policy

b. Stop Vpn client

c. Remove checkpoint secure remote “v” on local area connection properties ( do it only for testing – remember if you remove the “v” user will be not able to dial VPN.

4.      Run Outlook.exe with rpcdiag switch “outlook.exe /rpcdiag” see where is hanging

5.      On exchange system manger open user related mailbox store in logons section check if user exceeded maximum of 32 connections to the store.

a. If do : To solve this problem for this user, download the sysinternals tool called TCPView and run it on your Exchange server. You will see a whole bunch of connections. Work out the IP address of user, and then using TCP view terminate all sessions to that IP address.

b. Other option is to mount / unmount store – not recommended

6.      In order to Increase default 32 MAPI connections limit do the following things

a. Click Start, click Run, type regedit in the Open box, and then click OK.

Locate and then click the following registry sub key: HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesMSExchangeISParametersSystem

If the Maximum Allowed Sessions Per User entry does not exist, do the following:

On the Edit menu, point to New, and then click DWORD Value.

Type Maximum Allowed Sessions Per User as the entry name, and then press ENTER.

Right-click the Maximum Allowed Sessions Per User entry, and then click Modify

Click decimal, type the value that you want to set in the Value data box, and then click OK.

Exit Registry Editor.

Click Start, click Run, type services.msc in the Open box, and then click OK.

Click the MSExchange Information Store service, and then click Restart Service.

Didn’t solve the problem ? Read Related Microsoft solutions

http://support.microsoft.com/kb/842022

http://support.microsoft.com/kb/830836

http://support.microsoft.com/kb/840835

http://support.microsoft.com/kb/821188

http://support.microsoft.com/kb/821188

http://support.microsoft.com/default.aspx?scid=898060

Outlook doesn’t open EML attachment or EML files saved on desktop.
The solution is simple..
Uninstall Google Desktop Search