我无法复现因 SiteSetting.disable_emails 导致消息无法发送的问题，但我已修改脚本，仅在返回 EmailLog 时报告成功，并针对 disable_emails 设置添加了额外警告。
$ bin/rake 'emails:test[]'
Testing sending to using localhost:1025, username: with auth.
SMTP server connection successful.
Sending to . . .
Mail was not sent.
Reason: message.to is blank
### WARNING
The `disable_emails` site setting is currently set to non-staff.
Consider changing it to 'no' before performing any further troubleshooting.
以及
Sending to michael@example.com. . .
Mail accepted by SMTP server.
Message-ID: dfaf1c88-aab6-474b-b50c-8c500afb6291@localhost
If you do not receive the message, check your SPAM folder
[...]