Hi ajl-bookkeeping,
Thanks for reaching out and I'll do what I can to help you figure out why your email isn't working now. It's great that you've touched base with your IT guy. I'll take it from here.
Knowing more details about the situation, including which version and year of QuickBooks Desktop you're using, when the issue began, what error messages you're seeing, and so on, would be beneficial for narrowing down what's going on. For instance, if it stopped working as of the beginning of June, I suspect you may be using QuickBooks Desktop 2016 as functions relying on Internet connection and other services in the program were discontinued at that point. Learn more about that here: QuickBooks Desktop service discontinuation policy and upgrade information
If you're using a newer version, however, please start by making sure your email's configuration hasn't changed. The Set up email service article can help by showing you how it needs to be set up. The article's Set up Secure Web Mail section also notes that it's not supported for QuickBooks 2017 R4 releases and older. To check which release you're on, press F2 on your keyboard. If you need to update QuickBooks Desktop, click Help in the upper toolbar of the program, then Update QuickBooks Desktop.
Otherwise, give our phone support team a call at 1-877-772-9158. Pro and Premier agents are available 24/7. Enterprise agents can help from Monday to Friday between 9 a.m. and 8 p.m. EST.
I hope that helps. Take care!