Cannot send invoice by email. Receive the error: We are unable to connect to the email server for your email provider.

Hey there, @SMarrs. 

I can provide you with a few basic troubleshooting steps that you can take to help resolve this issue. It's very simple and easy. Just follow below. 

Solution 1: Update to the latest release

1. Go to the Update to the latest release page. 
2. Ensure your product is selected. If not, choose your QuickBooks product within the Change link. 
3. Press the Update button to download the update file. 
4. Pick Setup Automatic Updates to learn how to set QuickBooks to automatically download and install the latest updates. 

Solution 2: Check the settings in the webmail preferences

1. Choose Preferences from the QuickBooks Edit menu. 
2. Pick Send Forms on the left-hand side. 
3. Under "My Preferences," select the email account you're using and then Edit. 
4. In the Edit Email Info screen, go to the SMTP Server Details section and set the server name and port to your email provider settings. Refer to Set up your email service in QuickBooks Desktop for a list of SMTP Server and Ports.

If you're still running into issue after trying these instructions, then check out this link about fixing the error: could not connect to the email server. 

Touch base with me once you've tried these steps. If you have any other questions, just let me know. Have a good day!