Playing chess via E-Mail is actually quite similar to playing correspondence chess. There are certain advantages of playing E-Mail Chess, one of which is the response time. Instead of waiting for days before receiving a reply from the other party, you can now receive replies within minutes after the your opponent has posted his move.
For this purpose, the IECG (International E-Mail Chess Group) has been established in 1994 by several chess players. The membership base has grown tremendously throughout the years, there are now more than 3800 members from 68 countries and the numbers are growing daily. Send an E-Mail to the IECG Tutorial Office to register.
Aside from IECG, you can also join S.E.M.I. (Scacchi E-Mail Italia) which also provides similar services offered by IECG.