Why does the From field in our emails says "On Behalf" or "via" and does not reflect the sender's email address?

Question:

I sent an email from my email address: john.doe@mycompany.com. In the email, the From field shows via or on behalf of john.doe=mycompany.com@delivery.mycompany.com. Why does this happen? I want the From email address to show as john.doe@mycompany.com.

Answer:

This is known as On Behalf Of notation and is an issue in how Outlook display the sender email. Gmail will usually display the From email address as it is. The way to eliminate this notation is to ensure that the email sending domain configured in your Email Services settings and the From field use the same domain. 

For example, if your email sending domain is delivery.mycompany.com, your From email address should be john.doe@delivery.mycompany.com. Doing this will also remove the "on behalf" or "via" from the From field.