how much memory should a script use?

[eluser]ggoforth[/eluser]
I've recently installed CodeIgniter to run via command line and Cronjobs. This works great, but I'm worried in the future as I get more users my scripts will run out of memory. As of right now, I'm running the php script directly using the PHP interpreter, so I'm not using a wget or anything like that. I've set the time limit to 0 so it won't timeout. I've also upped the memory limit to 64 MB. My application is a Appointment reminder system, so if I have 100 users, that average 5 appts a day, that's 500 emails I will be sending nightly. Will 64 MB be enough memory to accommodate this? I'm not really a server tech so I'm not sure how much memory is typically used, or things I can do to keep this lower. Any advice would be great!

Thanks in advance.

Greg

[eluser]Mareshal[/eluser]
http://bambooinvoice.org/ - this is created by Derek Allard(CI staff) using CI, and when I've added benchmarks I saw is using at most 2.1MB RAM, so 64 is more than enough. But if you have problems with ram, us eAccelerator and the script will use at most 1MB(mine is using 0.4 all the time now)

[eluser]ggoforth[/eluser]
Hmmm, ok. I can't image a script sending 500 emails at a time would only use 1 MB of memory. Can anyone else say if this is the case? I just want to make sure my logic is not flawed, and sending that many emails at one time is ok, or if I should create some sort of que and only send a few at a time.

Thanks for any advice.

Greg