BIP email's font appear diffrent within gmail than outlook

Summary:

Customized email's fonts appears diffrent

Content (required):

I'm designing a BIP template with the kind of rtf format.

I'm designing one of the journeys OOB reports.

the template uses the Open Sans fonts.

when it being sent it seems to apear diffrent in gmail than outlook.

the outlook present the right font while gmail isn't.

attaching document with the outlook

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

How it apears for gmail (Employee email):

 

How it appears to outlook (manager) (working as expected!!!) :