Design email template to be sent to clients

Hi, i need to send emails to the clients. i want you to provide a email temaplte whcih i can send to clients but which doesnt get stopped by [login to view URL] you see freelancer emails, these are not blocked by image fiilters and gmail. i need a proepr system or workflow on what to be done and ONE email template to be provided whcih i can edit and send with different content next time