How to send a email if a condition is executed?

In other topics i saw that we need to use a log statement and then link this to a email notification. How do i do this?

My real problem is this: we have a monitor for pool members and it makes a http request to check if the they are responding. We need to check if a word comes in the receive string, but it seems that the receive string does not contain the entire web page requested. How can i do to get this entire string?

And if the word does not come in the string, how to send an email to notify us?

Like i said, i'm new to it, so sorry if i wrote any illogical thing.

Thanks!