[drupal-support] mass mailer says can't fine php executable even though it's in /usr/bin/

[Petre Scheie]

I installed the mass mailer module, and can create messages, but no 
messages are being sent out.  Looking in the message queue, I see

"You do not have the php executable in your system path and it cannot be 
located in
/usr/bin or usr/local/bin."

But php IS in /usr/bin, with 755 for permissions.  Why can't it see it?
TIA.

Petre Scheie