[Koha] Add time lapse between notices when sending emails.

Dear All, When sending advance or overdue notices, the emails are not sent / failed. This happens because the a number a emails are sent per second and univerity mail server has some restrictions. I'd like to add a time lapse of a couple of seconds between emails. Is it possible to do this? With best regards, Naveen Ali ITM-JE (EAKL) Inst Representative for HEC Digital Library Resources. NEDUET, Karachi.