When extracting a message from my inbox containing the norwegian letter "ø" I find that it is encoded with 3 bytes as "=F8" or hexadecimal "0x3d4638". In UTF-8 the letter "ø" is encoded with two bytes as "0xc3b8", whereas in ISO-8859-1 it is encoded as one byte with code "0xf8".
What kind of encoding is used by my mail server when it saves incoming mail? That is, in which encoding is "ø" equal to "0x3d4638"?