Grant Access by IP Address, Subnet, or Domain

If you have a small number of clients who use the IMAP4 service, you can create an exclusive group of computers that can access only the server. Computers that have access to the service can be identified by IP address, subnet mask, or domain name.

Warning   Identify a permitted computer by IP address only if you assign IP addresses statically. If a Dynamic Host Configuration Protocol (DHCP) server assigns temporary IP addresses to computers, you cannot ensure a computer will always use the same IP address.

To grant access by IP address, subnet, or domain:

1. Start System Manager
   on the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
2. Navigate to IMAP4.

   System Manager

   1. Administrative Groups
   2. Administrative group
   3. Servers
   4. Server
   5. Protocols
   6. IMAP4
3. In the console tree, right-click a virtual server, and then click Properties.
4. On the Access tab, click Connection.
5. Click Only the list below, and then click Add.
6. Select one of the following options:
   • IP address. Type the static address of a single computer; for example, 192.168.114.201.
   • 
     
     

     Tip   If you know only the name of the computer, click DNS Lookup. Type the name of the computer, and then click OK. If resolved, the IP address appears in IP address automatically.

   • Group of Computers. Type the subnet address and mask; for example, a subnet address of 172.17.131.0 and a subnet mask of 255.255.250.0.
   • Domain. Type the complete domain name; for example, nwtraders.microsoft.com.
7. To add the computer, subnet, or domain to the list of permitted computers, click OK.

Note   By default, IMAP4 virtual servers grant all computers access to Exchange resources such as public folders and mailboxes. If you create groups of permitted users for one IMAP4 virtual server, the list applies only to that one IMAP4 virtual server. To limit access to other IMAP4 virtual servers, you must add groups of computers to all IMAP4 virtual servers.