The text of my e-mails sent by foreign character is garbled

The text of my e-mails sent by foreign character is garbled

Hi I have input foreign character in my zoho mail and it seem all right but when i sent it then i checked up in my sent folder that the character was all in garbled.

The English was fine but not other than that.

The content was showing something like ?????...????

Please fix it ASAP as we got customer not only from English speakng countries.  It was working well but not the recent time.