Supporting Messaging Clients

Grant access by IP Address, Subnet, and Domain

If you have a small number of clients who use the POP3 service, you can create an exclusive group of computers that can access the server. Computers that are permitted to use 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, and domain:

  1. Start System Manager
    on the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
  2. Navigate to POP3.

    System Manager

    1. Administrative Groups
    2. Administrative group
    3. Servers
    4. Server
    5. Protocols
    6. POP3
  3. In the console tree, right-click a virtual server, and then click Properties.
  4. On the Access tab, click Connection.
  5. Select Only the list below, and then click Add.
  6. Select one of the following options:
  7. To add the computer, subnet, or domain to the list of permitted computers, click OK.

Note   By default, POP3 virtual servers grant all computers access. If you create an exclusive group of permitted users for one POP3 virtual server, the list applies only to that one POP3 virtual server. To limit access to other POP3 virtual servers, you must add groups of computers to each instance of a POP3 virtual server.