If in doubt, use the full block. It's simpler and seen as a wholly acceptable format for all official letters, largely because it is the more formal_looking of the two. Sender's Address _ The address of the sender will be the first thing to appear on the letter. As you can see in the examples above, its positioning differs depending on the format: Full block format (or FBF for the purposes of this article): Align left. Modified block format (or MBF): Align right
The third and last paragraph provides means to follow up your application. You can slightly review what you have previously mentioned in the letter to provide more emphasis. You can also provide means for contacting you in case you are considered in the next phase of the application process.