Read your mail from in a folder.
{"msg":"Mail","action":"ReadMail","folder":"inbox","mail_id":0}

If the mail exists from the account's folder:
{"MSG":"Mail_Data","To":"foo2","From":"foo","Subject":"example subject!","Message":"hello world!","Invite":null,"ReadStatus":0}

If the mail doesn't exists from the account's folder:
{"MSG":"MailNotFound"}

If you are not logged in:
{"MSG":"MailLoginRequired"}