For my work, I am making a web application for our intranet that will query our accounts, and based on the input, will pull out the appropriate contact's email address to send a pre-scripted message.

I can't seem to find a good answer on the net, but my question is: What is better for the mail server as far as not overloading it?

-to send the email in bulk (will be about 100-200 recipients)?

or

-to queue them one by one in a loop? and if so, should I program some sort of delay?

Any help would be much appreciated

Thanks,

Gil