Thanks, Yasi :-)
Click here for more info about Imam Khomeiny.
Interesting to note that the Iranian postmark (at the back of cover) follows Iranian calendar, which is different from the international accepted Gregorian calendar. It is also different from the Islamic calendar (or Hijra calendar). For instance, year 2010 (Gregorian) = year 1431 (Islamic) = year 1389 (Iranian).
The Iranian new year usually falls on 21-24 March.
Therefore, March 2010 (Gregorian) is the first month of Iranian calendar in the year of 1389.
By calculation, 25.8.1388 (Iranian, as in postmark) is equivalent to 16.11.2009 (Gregorian).