Hello there, @kianmehr.
When you're unable to send an email to your vendor, you might need to reset your email address in QuickBooks.
To reset your email:
- Go to the Gear icon.
- Under Your Company, select Account and Settings.
- In the Contact info section, review each email address, then make changes as needed.
- Click Save and then Done.
You can also email customize sales form on your QuickBooks Online.
Let us know if that works for you and if you have additional questions. Take care and keep safe.
