Polish language email

Is there a way I can type it in English, then translate and send it?

You can type it in a program like TextEdit, then copy/paste it in an online translator like

http://www.poltran.com/

Then copy/paste again into Mail.

To compose directly in Polish, go to system prefs/international/input menu, check the box for Polish (plus the box for "show input menu in finder"), then select Polish in the "flag" menu at the top right of the finder, and type.

Machine translation can sometimes give totally incomprehensible or erroneous results

What about typing the eMail in polish? How can I find a Polish font? and if so, how do I get it where I can use it?

Everything is already built-in. Just follow the instructions given earlier, i.e:

To compose directly in Polish, go to system prefs/international/input menu, check the box for Polish (plus the box for "show input menu in finder"), then select Polish in the "flag" menu at the top right of the finder, and type.

To see which key does what, activate Keyboard Viewer, done the same way you activate a Polish keyboard.