Sender name mail in template html with golang

I want to send email with golang, but I have a problem,

I want to parse the sender name ( ex: Sender ex@mail.com) in template file html because I have multiple template with mail, when I put the email in template file, it doesn't work, it says :

" error: 501 5.1.7 Bad sender address syntax"

Is there another way to put this sender name in html file ? a particular syntax ?

Thank you