The CodePage property specifies how strings are encoded in the intrinsic objects. A code page is a character set that can include numbers, punctuation marks, and other glyphs. Codepages are not the same for each language. Some languages such as Japanese and Korean have multi-byte characters, while others like English and German only need one byte to represent each character.
Sets or returns an Integer value
Setting Mailing.CodePage explicitly affects the default code page for the mailing, where Mail.CodePage affects all content of a mail message.
Mail.CodePage, Response.CodePage