Desktop pro 2017 email does not work inside Quickbooks

Transferred my desktop Pro 2017 onto a new laptop. Cannot get Quickbooks to email invoices or other documents. Spent many hours investigating and trying to figure it out. Through AI help I was able to get a special password which supposedly is required because Quickbooks does not recognize your normal password for whatever email address you’re using. Got it to work once but Quickbooks didn’t save the password. How do you get Quickbooks to email out documents and save the password which sends them rather than go through that whole process of getting a special password.