Intro

Eb6 Eb6 Eb6 Eb6

Verse
     Eb6       Eb6
Four score years
   Eb6        Eb6        F       Eb6
Living down in this rain swept town
    Eb6      Eb6
Sea salt tears
     Eb6      Eb6      F          Eb6
Swimming round as the rain comes down

Chorus

Bb   Bb  Bb  Bb             Eb6    Eb6Eb6
Mr. Postman...do you have a letter for me?...

  Ab         Ab
A letter for me...
        Eb6      Eb6
From my own true love...
Bb   Bb   Bb  Bb
Lost at sea
        Eb6
Lost at sea

That just repeats through the whole song. It sounds right to me when I play along with 
music. I hope the chord names were right...