This post will show you how to remove the text “on behalf of” that appears in Gmail emails for FREE!
It is assumed
[1] You have set up your original mail account using cPannel
[2] You have linked the email with a separate Gmail account
In your Gmail account (example for[1] Click cog/settings on right hand side and then click on settings.[2] Click Accounts and import (blue top menu)[3] Next to Send Mail as (or your email) click  edit info then next step[4] Choose Send through SMTP servers[5] Fill in with the details below

SMPT server: and Port 25 (more generally )
Username: (your email)
password: your password
Tick Secured connection using TLS
6] Save changes.