Restrict relays

A common concern that you might face is protecting your server from people who try to use your e-mail server for spamming, or sending large amounts of bulk e-mail. To avoid these problems, use the relay restriction function to specify as closely as possible who can use your server for relay.

1. In iSeries™ Navigator, expand your iSeries Server > Network > Servers > TCP/IP.
2. Right-click SMTP and select Properties.
3. Click the Relay Restrictions tab.
4. Select the appropriate relay restriction from the six options offered here.
   Note: If you choose Accept relay messages for only recipients in the near domains list or Accept relay messages using both the near domains and address relay lists, then you will need to click the General tab to list the near domains from which you are accepting relay.
5. Click Help for more information.
6. Click OK.
7. If the SMTP server is currently running, you need to end and restart the SMTP server for the changes to take effect:
   1. Right-click SMTP and select Stop.
   2. Right-click SMTP and select Start.

• Accept relay messages from Post Office Protocol clients
  One of the options for relay restriction enables Post Office Protocol (POP) clients to relay messages through Simple Mail Transfer Protocol (SMTP) for a specified period of time after they log on to the POP server.
• Use relay restriction and connection restriction functions together
  i5/OS™ enables you to use the relay restriction function along with the connection restriction function to carefully control who can access your e-mail server.