Naturally, EDI messages can also be distributed through e-mails. Here, too, we can distinguish between two types of correspondence. The more widespread, but also more problematic correspondence method uses Internet mailboxes and the SMTP standard recommendation. Although Internet mail is a cheaper solution, in today’s world of spam and counter-spam filters its use is problematic in automated business relations. There is no standard for zipping and extraction for SMTP envelopes, which makes these processes ad-hoc. Nowadays, it is becoming less frequently used due to Internet mail being inundated with spam.
The more standard and “professional” correspondence method uses X.400 mailboxes for message transmissions. The X.400 business correspondence service is simply absent from the history of telecommunications in Hungary, which even today causes major problems in business and administration-related electronic correspondence. This is why it is still not possible to send “registered” and “return receipt” e-mails that would be officially accepted under current standards. In Western Europe and North America business correspondence systems remain the backbone of official correspondence . EDI is fundamentally a business and administrative system; therefore it was logical that EDI message transmission should take place on a business correspondence system that employs the X.400 standard. This is the type of EDI that the aforementioned VANs mostly use in their internal networks, placing EDI messages in an X.400 correspondence envelope according to the X.435 standard. In most cases, the connections between VANs also take place on an X.400 network. Due to the absence of an X.400 backbone network for correspondence the use of X.400 is still not widespread in Hungary for EDI transmissions, but certain EDI providers can provide such a connection upon request.