How to seamlessly switch between spelling languages in Mail? I write my emails in two languages. So system-wide spelling language setting is not very useful for me, since in span of working day I usually write half of my emails in one language and half in another. Now the current spelling language switching mechanism is not very good. First of all I need to invoke spelling window with CMD + : then change the language, then close the window, refocus my mail window and then continue writing. Also the spelling with the new language is applied only to the text I am entering after changing the language. Previous text is not spelled, unless I click each word individually. 

So I have the following questions:


Does there exist a quick method to change the language? Keyboard shortcut? List of the languages appearing after right click the way it is organised in Google Chrome?  Maybe there is a possibility to associate spelling language to keyboard layout? I use different layout for different languages, so this would be very natural.
How to automatically apply spelling to the text which was entered before the change of the language?


I use Mac OS X 10.6.6.
I have just spent some time with Mountain Lion after I added a custom dictionary (Afrikaans) to the ~/Library/Spelling folder (.dic and .aff).

Findings:
- If I set the "Spelling" in "System Preferences -> Language and text -> Text" to Afrikaans, the Afrikaans spell check works great.
- If I set the "Spelling" to "Automatic by language" detection between English and Afrikaans it does not work correctly. It never recognises Afrikaans, checks everything as English.

So in mail.app the only workable option seems to be to set it up to check email upon sending, and to select the language at the bottom of the pop-up box.

Alternatively buy Postbox, where you can install a Thunderbird dictionary and select the language manually. But Postbox is not doing retina displays (yet) - it looks awful at the moment on retina.