How do you change the "From" address in the WordPress email notifications?

When WordPress sends out an email notification, the “From” address is wordpress@mydomain.com. I want to change WordPress to another email address. I’ve searched WPMUDEV and online and have found several solutions but none seem to work with my Multisite install.

Does the email function work differently from a single site install and if so, is there still a way to change “From” address in Multisite?

I found some SMTP plugins that allow you to connect your WordPress install to an actual email server (Gmail) to send notifications. This is supposedly more reliable as php mail often gets trapped in SPAM filters. Do you think it’s a good idea to use one of these plugins, and if so, this should solve the problem I’m having with the WordPress email address, correct?

Thanks for your help,

Trevor