I am facing this issue with My Mac Outlook 2011 Please help me out.

When I forward mail from Mac Outlook 2011 Version 14.5.4 to Any Windows User, line space automatically get increased 2 or 3 times. Font size and type also Changes on Windows Outlook(Suppose while drafting I selected all content of email and made choice of Arial Font, then some of the line appear as Times New Roman font in Windows laptop . My Mail Server is Microsoft exchange server 2007. I have checked 3 Profile same issue coming.

See the below 

Mails example to understand better.

Forwarded Original Mail ( Mac Outlook ) 

Hello XYZ,

Please find attachment 

Do all needfull 

On urgent basis

Thanks 

ABC

Received Mail On ( Windows Outlook ) 

Hello XYZ,

Please find attachment 

Do all needfull 

On urgent basis

Thanks 

ABC