Glad to have you here. If only one of your company files is having an issue sending emails, there are a few possible reasons why this is happening:
The email preference is misconfigured.
A damaged QuickBooks installation.
Domain admin was blocked.
Account security settings from your email provider.
First, we want to make sure your QuickBooks Desktop software is in its latest release. QuickBooks periodically provides maintenance release and product (software) updates to fix emailing concerns, add features and enhancements, and update compliance information.
Second, let's check your email preferences in QuickBooks:
At the top menu bar, click Edit.
Click Send Forms on the left panel.
Under My Preferences tab, select the email account you're using.
Someone from our Technical Support Team would also be glad to help you with this. They have the tools necessary to check your company file and help you send emails. Here's how you can reach them:
Go to Help, then QuickBooks Desktop Help.
Click Contact Us.
Give a brief description of your issue, then hit Continue.
We’ll provide you a few support options. Choose which one is best for you.
Please be aware, due to the growing impact of the COVID-19 situation, we are currently experiencing staffing challenges. For QuickBooks Desktop, we encourage you to message us, but please note wait times for a response may be longer than usual. We appreciate your patience.
Please feel free to let me know if you need any help. Take care.