Run on behalf of allows agents to be set to run on someone else's id.
This is obviously useful if certain documents need limited access.
Be careful when using this with agents that take parameters from the Querystring eg:
SuperAgent?openagent&user=Adam&action=delete : )
This option also means that any mail sending will be done from this id.
Though I presume using the Principle field will still allow overruling of the sender .
So if your agent is sending email on behalf of someone else in R6 and you don't know why check this new feature. To check or set it, open the agent and then open properties box if not already open, select Agent and click on the key.
In Notes 5 this would have to be done by signing the agent with the relevant id, which could be a pain, or may be using the principal field.
NB: Security for this feature requires either Unrestricted or in Notes 6 there is a special agent security group:
"Sign agents to run on behalf of someone else:" in the security tab of the server document.
If you do not have the right access you will get this error message:
HTTP Web Server: Lotus Notes Exception - Error validating user's agent execution access
This can also be used to redirect bounce back messages to another user or mailbox ...