Font changes ONLY for text with URL links when send test email

Hello,

I am using one of the e-mail safe fonts (Trebuchet MS) in an e-mail newsletter. The font appears as expected in the test email sent to my team (who are all on Outlook, as our most of our subscribers), EXCEPT when the text has a URL link. In this case, the font changes to Arial, even though the rest of the text displays as Trebuchet MS. Also, text with email links do not change to Arial in the test email.

Is there any fix for this?