Sending email using Smtp.mail.microsoftonline.com

Question

The context:

We’re a small company that does not have an Exchange Server (or anyone dedicated to it) yet we still need to have/send emails.

Answer 1

What worked for me was what the-dude suggested Send SMTP email using System.Net.Mail via Exchange Online (Office 365) , on changing the email "from" address to be the same as the login for the stmp address

AND

doing what Vince suggested at the end Sending email using Smtp.mail.microsoftonline.com for commenting out "smtpClient.UseDefaultCredentials = false;"