Character set conversion and message reformatting
One very basic mapping table in the MTA is the character set conversion table. The name of this table is
CHARSET-CONVERSION. It is used to specify what sorts of channel-to-channel character set conversions and message reformattings should be performed.
On many systems there is no need to do character set conversions or message reformatting and therefore this table is not needed. Situations arise, however, where character conversions must be done. For example, sites with enclaves of local users accustomed to using older charsets such as ISO-2022-JP (for Japanese) or KOI8-R (for Russian) may wish to convert messages outbound to the Internet into the general UTF-8 charset, to increase interoperability with remote Internet correspondents.