The Canonical Internet vs X.400 Debate

It is not an attempt to end the debate, rather an attempt to make a list of points that have been raised before, so that new contributors to the battle can bring new weapons to the battlefield rather than trying to use rusted swords and broken maces when maintaining the tradition.

Other parts of the X.400 FAQ Web will concern the issues involved with coexistence and harmony between the protocols; this part attempts to take the adversarial stance encountered when someone has to make a decision to buy one system or the other.

What we are comparing

• X.400/92, as defined by the ITU and ISO in the X.400 series of standards, with some ISO-only additions in IS 10021. See the List of Standards to get the (reasonably) complete list of relevant standards.
• Internet Mail, as carried by SMTP, using MIME as the message format, and with extensions to do 8-bit transfer, delivery notifications and so on.

The list of points

Some of the points are hotly disputed by one or the other party; this will be listed in the supporting documentation.

• X.400 is defined by the ITU, Internet Mail by IETF
• X.400 is specified in US GOSIP and government contracts
• X.400 is defined using ASN.1, Internet Mail using EBNF
• X.400 is a binary format, Internet Mail looks like text
• X.400 has functionality that Internet Mail hasn't
• X.400 has attachments, Internet Mail has attachments
• X.400 has delivery notifications, Internet Mail has NOTARY
• X.400 has receipt notifications, Internet Mail hasn't
• X.400 has Message Store, Internet Mail has POP and IMAP
• X.400 has an EDI format, so has Internet Mail
• X.400 has an integrated directory service
• X.400 addresses are ugly
• X.400 (88) breaks X.400 (84); MIME doesn't break old mail
• X.400 has security defined; Internet Mail has PGP, PEM and MOSS
  
• X.400 has fewer products than Internet Mail
• X.400 products are more expensive than Internet Mail
• X.400 mail is more expensive to use than Internet Mail
• X.400 products are conformance and interoperability tested

  (after this point there are only empty documents)

• X.400 has better gateways to CC:Mail than Internet Mail
• X.400 is store-and-forward, Internet Mail is point-to-point
• X.400 mail guarantees delivery
• X.400 is slower than Internet Mail
• X.400 has far fewer users than Internet Mail
• X.400 runs over OSI networks; TCP/IP can be used by both
• X.400 can be managed using CMIP
• X.400 has fax gateways; Internet Mail has too.
• X.400 routing is manual; Internet Mail is routed on DNS
• X.400 suppliers will stand up in court
• X.400 messages are harder to fake than Internet Mail

• favours X.400
• favours Internet Mail
• doesn't favour either party

Until this gets going, you can indicate your opinion on the future of X.400 by betting on the "X400" claim in the Foresight Exchange market at www.ideosphere.com.