Within the Letterman component there were spelling and grammatical errors in the confirmation subscribe and unsubscribe emails sent to new users.  The file that I have edited to correct some of these is; /administrator/components/com_letterman/language/english.messages.php 

The changes include;

• Line 7 - changed from "you have been..." to "You have been...."
• Line 23 - changed from "you have been unsbscribed..." to "You have been unsubscribed..."
• Line 24 - changed from "thanks for..." to "Thank you for.." and
  
• Line 31 - changed from "You're..." to "You are..."
• Line 44 - changed from "Newsletter could not be send!" to "Newsletter could not be sent!"
• Line 118 - changed from "Your email Address" to "Your email address"

For any Letterman support questions post them to the Letterman Forum located on the J!Factory site!