Am I able to change the email server used for administrative messages?

[Scissor]

I am running Plesk 9.5.2 for Windows.

I don't want to any of my webs to use 127.0.0.1 (localhost) for sending out emails. But Plesk does this for administrative notifications.

I was able to specify an alternate email server for both my WordPress blog sites and UBB.Threads message boards, but I don't seem to be able to find how to do it on Plesk. (Originally both these webs simply used localhost from php.ini, but allow it to be overridden in their control panels.)

Is there a way to tell Plesk to use an alternate smtp server without modifying PHP.INI?