eNewsletter - question about cron jobs

I've never created a cron job or even know what it is exactly. I know it is used to run scripts at specified times, but thats all i know. :slight_smile:

Sooooo, Im using the eNewsletter plugin, and I am using smtp method. Just wondering is there any issues if the list gets too large? Can you use smtp method without cron regardless of how large your list is?