评论系统邮件提醒功能

[beiminglongkun]

Is your feature request related to a problem?

当收到评论时进行邮件提醒。

Describe the solution you'd like

可以由管理员配置邮件服务，当收到评论时，自动提醒被评论者。

Additional context

No response

[Issues-translate-bot]

Issue is not in English. It has been translated automatically.

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Title: Comment system email reminder function

[boojack]

Duplicated with #858