내 포럼에 문제가 있는 것 같습니다

There seems to be an issue with my forum. It’s unable to send registration confirmation emails, which prevents users from completing their registration. It appears to be a problem with Sidekiq. Where can I adjust the settings to fix this?

This is not a problem with Sidekiq, but a problem with your SMTP server. You should contact the company where you are getting your SMTP services from and complain / ask for help there.