Only if the db is open at the time, or if you don't want to depend on that, you'd have to use Windows Task Scheduler. With TS, you can create a repeating task to open a db that does nothing but this task, or you can open the same db as everyone else uses with a command line switch in a shortcut. You'd probably want to capture that a switch was used when opening the db if it's the same db that everyone else uses so that you can bypass any code that requires user interaction as well as close the db when the task is complete. AFAIK, TS has the option to run even if no one is logged on to the pc where the task was created.
Otherwise, you'd need to compare the date of last emailing against the current date and initiate a prompt to start the process.