Can the default font size for "Email this Page" text be changed in Mountain Lion? In Mountain Lion, Safari has a new method of "Email this Page" which opens up a new mail message where the web content can be shown as a page, pdf, or a link.

If one chooses "Link", the font type and size for the link text is the default the user has chosen for messages in the Mail.app preferences. However, any text that the user can add to the the message now defaults to Helvetica 12 pt.

Is there a way to change the default for text size, either in a preference or through the terminal? 

Here's an example of what I'm talking about, where the link text is Helvetica 16 and any additional text added defaults to Helvetica 12.

http://www.qwip.org/pictures/EmailLink.jpg
There are several ways to do that. 

The easiest way would be to install a Plugin which formats outgoing E-Mail and give you the option to change specific characteristics to you liking (Font, Size etc.). For that you should look into the following Plugins:


MessageFont


  "WYSIWYG for your outgoing emails If Outlook for Mac, Thunderbird and
  other email apps can set the default composition font1, why can’t
  Apple Mail? With MessageFont, you can! MessageFont lets you set Apple
  Mail’s default composition font for new rich text outgoing messages. [...]"

Universal Mailer


  "Universal Mailer is a Mail.app plugin that solves some issues when
  sending emails. It removes ATT00001.htm files, it correctly formats
  messages with attachments and inline images and offers an option to
  set the default font for outgoing messages. [...]"



Another way would be to change the default Font Size via the Terminal, f.e. in 24, open up the Terminal and type in:

defaults write com.apple.mail MinimumHTMLFontSize 24


That will change the Font to 24pt, but that includes the Page you want to forward from Safari if you choose 'Webpage'. If you just forward the Link everything should be fine.