Thank you for reaching out to us, MTMama.

I'll be glad to help you with your email concern.

It has to be manually changed whenever your emailing the forms.

To Set up webmail to work with QuickBooks.

Here's how: 

1. Click the Edit option.
2. Choose Preferences.
3. Click Send Forms.
4. Choose WebMail.
5. Click Add.
6. Provide the Add Email Info.
7. Click OK to save the changes.

You can also check on this article: Fix Error: Could not connect to the email server for more information when you experience a connection error to your email server in QuickBooks.

We're always here in the Community to help if you have other questions related to emails in QuickBooks. Stay safe!