I don't have permissions to send emails on my own behalf

It turns out that the users somehow created alternate credentials in Windows. Outlook would then try to use those credentials when sending as the user which would cause it to fail. Just go to the Control Panel, then to Credential Manager, and remove any credentials that relate to your

 http://community.spiceworks.com/topic/206858-i-don-t-have-permissions-to-send-emails-on-my-own-behalf

export dhcp database

Export the DHCP database from Windows 2003:

1.                   On the Windows 2003 DHCP server, navigate to a command prompt

2.                   Type the following Command: netsh

3.                   Type the following Command: DHCP

4.                   Type the following Command: server <\\Name or IP Address>

5.                   Type the following Command: export c:\w2k3DHCPdb all

Note You must have local administrator permissions to export the data.

Import the DHCP database

1.       Copy the exported DHCP database file to the local hard disk of the Windows Server 2008-based computer.

2.       Install the DHCP Role on the server.

3.       Stop the DHCP server service on the server.  To do this, follow these steps:

a.       Log on to the target DHCP server by using an account that is a member of the local Administrators group.

b.      Click Start, click Run, type cmd in the Open box, and then click OK.

c.       At the command prompt, type net stop DHCPserver , and then press ENTER. You receive a "The Microsoft DHCP Server service is stopping. The Microsoft DHCP Server service was stopped successfully" message.

d.      Type exit, and then press ENTER.

4.       Delete the DHCP.mdb file under c:\windows\system32\DHCP folder.

5.       Start the DHCP server service.

6.       Right-click on the Command Prompt (cmd) and select run as administrator, to open the cmd prompt using elevated privileges.

Note You must have local administrator permissions to import the data.

7.       Type the following Command: netsh

8.       Type the following Command: DHCP

9.       Type the following Command: server <\\Name or IP Address>

10.   Type the following Command: import c:\w2k3DHCPdb

11.   Restart DHCP and verify the database has moved over properly.

Rules do not work automatically

Reset srs-file

Resetting the send/receive settings can be achieved by renaming the srs-file of your profile to .old. You can find the srs-file for your mail profile in;

• Windows Vista and Windows 7:
  C:\Users\%username%\AppData\Roaming\Microsoft\Outlook
• Windows XP:
  C:\Documents and Settings\%username%\Application Data\Microsoft\Outlook