Subject : Mails of host down

[TELCO]

Dear All ,

I need to configure approximately a time of about 5 minutes before they send mails of hosts down. With this I want to make sure that the equipment is really down so that so many mails by false do not arrive to me to alarm. What parameters would have to modify so that the mail is sent after the 5 minutes approximately that the equipment has down ???

Thanks in advance

Best Regards.
TELCO