"RFC-822=opresno(a)extern.uio.no @ GATEWAY]INTERNET/TELEMAIL/US"

To send an Internet message to a mailbox I once had on the X.400 host Telemax in Norway, I had to use the following address:

/I=D/G=ODD/S=PRESNO/O=KUD.DATASEKR/@PCMAX.telemax.no

To send from Internet to Telemail in the US, I have used this address:

/PN=TELEMAIL.T.SUPPORT/O=TELENET.MAIL/ADMD=TELEMAIL/C=US/@sprint.com

If you need to route your message through gateways, then complexity increases. One Norwegian UUCP user had to use the following address to get through:

nuug!extern.uio.no!"pcmax.telemax.no!/I=D/G=ODD/S=PRESNO/O=KUD.DATASEKR/"

To send a message from an X.400 system to my CompuServe mailbox,
I have used the following address elements:

Country = US
ADMD = CompuServe
PRMD = CSMail
DDA = 75755.1327

The addressing methods used on X.400 systems vary. Another example:
Some use the code C:USA rather than the ISO country code C:US. MCI
Mail uses C:NORWAY, C:USA, and C:SWEDEN.
Here are some important X.400 codes: