How do I disable the new user welcome email on multisite

I'm running a multisite installation, and I'm trying to configure the automated emails. When someone signs up for a site, they get a welcome email for signing up for a site. This includes their username and password to login to their new site they created. This is great. This is what I want. They also get an additional automated email with their username and password for my network. This seems kind of redundant, and I'm wondering if I can turn off the new user welcome emails but keep the new site welcome emails.

Any suggestions?