problem in displaying html file via email is not have proper format

[vadirajks]

Through Jenkins , i am trying to publish HTML file and sending the same file via e-mail. I can see published HTML file showing proper format inside the Jenkins without any problem but, full format in missing in the e-mail [ may be it is not properly rendering CSS and JavaScript].
I guess if it is Jenkins content security policy issue, it should have not displayed properly inside Jenkins. I don't see any problem in Jenkins.
Is this issue with email client? or is that email client not able to refer external CSS or JavaScript file?

Is there any custom template i have to use to overcome this problem.

Please help me to fix this.
Thanks,

[rajesh-ste]

I guess External CSS. email providers are not allowing external CSS