When should Jewish New Year cards be mailed this year?

== == Rosh Hashanah begins at sunset on 12 September this year (2007 CE).

Cards, therefore, should be mailed in time to arrive by ordinary post on 12 September.

Further to the above, it is now 2009 (5769 by the Jewish calendar) and this year Rosh Hashanah starts at sundown on 18 September - so the cards should be mailed at lest two or three days prior to that date if they're to arrive in time.