隐藏Outlook中的“发送者”信息

Is it possible to hide "sent by" information about mailgun in Outlook email client? That's how it's look like

Email has been sent by mailgun API from the server.

This is known as On Behalf Of notation. The way to eliminate this notation is to ensure that the email address for the Sender: field and the From: field use the same domain. For instance, for both the Sender and From field, they both need to end in either domain.com or mg.domain.com, whichever one is currently a custom domain on your Mailgun CP.

When sending, you should always make sure the domain you are inputting in the From: field matches the domain you have added and are sending from using Mailgun. If these domains do not match your messages have a high chance of getting marked as spam and showing up with "on behalf of" or "via".