这软件：Calibre，是不是在kindle上不能用了？

试了好几个文件，提示：
calibre, version 5.3.0 (win32, embedded-python: True)
无法通过电子邮件发送书籍: 失败: 把 自我的智慧 发Email到 7456@kindle.cn
Starting job: 把 自我的智慧 发Email到 7456xx@kindle.cn
Sending failed...
Traceback (most recent call last):
File "calibre\gui2\email.py", line 45, in run
File "calibre\gui2\email.py", line 129, in sendmail
File "calibre\utils\smtp.py", line 162, in sendmail
File "calibre\utils\smtp.py", line 126, in sendmail_direct
File "calibre\utils\smtp.py", line 37, in safe_localhost
File "socket.py", line 756, in getfqdn
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd4 in position 0: invalid continuation byte
Retrying in 1 seconds...
Waiting 1 seconds before sending, to avoid being marked as spam.
You can control this delay via Preferences->Tweaks
Sending failed...
Traceback (most recent call last):
File "calibre\gui2\email.py", line 45, in run
File "calibre\gui2\email.py", line 129, in sendmail
File "calibre\utils\smtp.py", line 162, in sendmail
File "calibre\utils\smtp.py", line 126, in sendmail_direct
File "calibre\utils\smtp.py", line 37, in safe_localhost
File "socket.py", line 756, in getfqdn
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd4 in position 0: invalid continuation byte
Job: "把 自我的智慧 发Email到 7456@kindle.cn" failed with error:
Traceback (most recent call last):
File "calibre\gui2\threaded_jobs.py", line 83, in start_work
File "calibre\gui2\email.py", line 102, in __call__
File "calibre\gui2\email.py", line 45, in run
File "calibre\gui2\email.py", line 129, in sendmail
File "calibre\utils\smtp.py", line 162, in sendmail
File "calibre\utils\smtp.py", line 126, in sendmail_direct
File "calibre\utils\smtp.py", line 37, in safe_localhost
File "socket.py", line 756, in getfqdn
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd4 in position 0: invalid continuation byte
Called with args: ('C:\\Users\\CHUANC~1\\AppData\\Local\\Temp\\calibre__n6aawys\\hvmtsdn8caltmpfmt.mobi', 'Zi Wo De Zhi Hui - [Mei ] Qiao Zhi _Fan Lun Te.mobi', '7456@kindle.cn', '电子书： 自我的智慧', '已添加, 你可以从中获取电子书\n\n自我的智慧\n\t由 [美] 乔治·范伦特\n\n使用 MOBI 格式.') {'notifications': <queue.Queue object at 0x00000248D9828FA0>, 'abort': <threading.Event object at 0x00000248D9838250>, 'log': <calibre.utils.logging.GUILog object at 0x00000248D9838F40>}