Big Business uses STARTTLS, usually on Port 587, to initiate a secure connection to SMTP email services like Webmail. When you are using a non-starttls setup, such as Port 465 for Gmail, click the Non Start checkbox to not use STARTTLS.
Sending with Outlook.com you can use your regular Password, or with Two-step Verification use an App Password.
Big Business includes advanced features for emailing, such as:
emailing with a service, like Gmail
You can use Big Business Mail to send emails directly, without using a desktop email client like Microsoft Outlook or macOS Mail.
This Solution provides setup details for Gmail. (6709)
Big Business Mail can send emails directly. For Gmail you need to authorize Less Secure App Access to avoid an AUTHENTICATION error (10113, pictured) in Big Business Mail. Go to your Google Account to Security to Turn On or Learn More.
This Solution provides setup details for Gmail. (7078)