Issues with button when sending test email

Issues with button when sending test email

I am currently creating email templates using the custom button feature. When I view the template on my chromebook and a test email sent to my Amazon powered email, the button(s) looks centered and normal. However, when other users in my company get the same test email to the same type of email account the button is either duplicated in an odd way or off-center. Is this an issue I can fix or is it something I am doing incorrectly?
uncentered button
duplicated button
what the button was supposed to look like