IF conditional on certain text existing in a cell.

I need to prune a bunch of email addresses based on domain name. I figured I would make the next cell a 1 if it contains the desired domain. I got it to work if that's all the cell contains with something like:
if(a1)="abc.com"1,0
But the cell will obviously have more than just abc.com, so how do I tell it to look for abc.com and don't worry about the rest of the cell? Sorry if this is too easy! Thanks !