I assume that many of you are wondering why HEBREW Font Arial is not showing in Outlook clients when sending Mail from Gmail Client.
The San Serif(Default Gmail font style) is showing on the web as Arial, but when Outlook clients recieving your emails they exposed to Default system font (David)
The Solution:
Create a signature in Text editor and set the Font to Arial. Then Copy the signature to Gmail Settings->Signature.
Thats it,
From now on your New emails from Gmail client will appear in Arial font on Outlook Clients.