Well I am afraid to try it to my user list in case it would take me a few tries and I would end up sending multiple emails to some users.
What I do know is by default php has a max time limit of 30 seconds in php.ini.
;;;;;;;;;;;;;;;;;;;
; Resource Limits ;
;;;;;;;;;;;;;;;;;;;
max_execution_time = 30 ; Maximum execution time of each script, in seconds (UNIX only)
I suppose I could change this, but I assume a lot of users who do not run their own server cannot. I believe sending out to even over a few thousand would take longer than 30 seconds, but I really dont know.
Will