How to Use sendmail in the Open Mode

In the Solaris 10 release, the sendmail service was changed so that it would run in local–only mode by default. The local-only mode means that only mail from the local host is accepted. Messages from any other systems are rejected. Earlier Solaris releases were configured to accept incoming mail from all remote systems, which is known as the open mode. To use the open mode, use the following procedure.

Running sendmail in the local–only mode is much more secure than running in the open mode. Make sure that you are aware of the potential security risks if you follow this procedure.

1. Become superuser or assume an equivalent role.

   Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services.

2. Set the sendmail properties.

   # svccfg -s sendmail svc:/network/smtp:sendmail> setprop config/local_only = false svc:/network/smtp:sendmail> quit

3. Refresh and restart the sendmail service.

   # svcadm refresh svc:/network/smtp:sendmail # svcadm restart svc:/network/smtp:sendmail