public Email GetEmail(int index) // 获取某封邮件(RETR指令) { if (Connected) { String RawEmail = SendCmd("RETR " + index, true); if (RawEmail.Contains("deleted") || RawEmail.Contains("not exists")) // 若邮件已经被删除,则不处理 { return(null); } return(MIME.GetEmail(RawEmail, index)); } return(null); }