"I was not able to send emails because I use gmail and just go to Gmail to get my mail via the web"

Which means you are using Web Mail, and not using an email "client" at all. Client = installed program.

"

• Unsupported Email Applications:
  • All 64-bit versions of Outlook, Outlook Express, and Windows Mail
  • All web-based versions of Outlook, Outlook Express or Windows Mail
  • All webmail services (such as Outlook.com, Outlook 365, Gmail, Yahoo, AOL, etc.)"

That's in the previously provided link.

It's not the address you have, but the way you access email. Web Mail doesn't provide a tool to connect to for local programs. There are ways to substitute your email address to an email service that typically uses a client, but that is not always provided for.

"If you are using a webmail service, you may be able to configure it for access through the MAPI email client installed in Windows. Our support agents cannot assist with setup of your email application. Please contact your local IT professional for further assistance, and let them know that you ll need a 32-bit, ExtendedMAPI-Compliant email client application to use this feature in ProSeries Professional. SimpleMAPI-compliant email clients may not function correctly."