8BITMIME ( RFC 1652 ) is an SMTP extension standardized in 1994 that facilitates the exchange of e- mail messages that contain octets outside the 7- bit range as established by ASCII . Before 8BITMIME implementations, email clients used various techniques to overcome the limitations of 7- bit encoding , these included encoding text to binary and the use of UTF-7 . However, these bypasses necessarily incurred bandwidth surges when transmitting non-ASCII data.

At least the following mail servers publish the 8BITMIME extension:

The following servers can be configured to publish 8BITMIME, but they do not fully implement the standard:

  • Exim (capable of 8 bit processing , but does not translate 8 bit to 7 bit messages when sending messages to endpoints that do not support 8BITMIME)
  • qmail (does not translate messages from 8 bit to 7 bit when sending messages to endpoints that do not support 8BITMIME, as required by RFC [5] , [6] )

Until June of 2005 , the following servers did not implement the extension:

  • Microsoft Exchange Internet Mail Service (version 5.5)
  • Netscape Messaging Server 4.15

See also