How to make pm automatically?

[tony]

(12-01-2012 09:13 AM)ZiNgA BuRgA Wrote:  It depends on how you want to approach the issue.
What do you exactly want to trigger the sending of the PM?  Perhaps a task?  When the user logs in?  That will determine where you should apply your modifications.

I would like for the pm to be sent automatically as soon as an user is a member at my forum for one year. No task or any other criteria such when they log in or anything. Thank you in advance

What is trigger btw? That the code above does not have it? And what hook should I use?