404. That’s an error.
The requested URL /_/+1/confirm?hl=ja&url=http%3A%2F%2Fmusyokuneet39jp.s1009.xrea.com%2F2021%2F04%2F23%2F%25e5%25a4%25aa%25e9%2599%25bd%25e5%2585%2589%25e7%2599%25ba%25e9%259b%25bb%25e5%25a2%2597%25e5%258a%25a0%25e3%2581%25b8%25e3%2580%2580%25e6%25b8%25a9%25e5%25ae%25a4%25e3%2582%25ac%25e3%2582%25b9%25e3%2581%25ae%25e5%2589%258a%25e6%25b8%259b%25e7%259b%25ae%25e6%25a8%2599%25e3%2581%25a7%25e6%2594%25bf%25e5%25ba%259c%25e6%2596%25b9%2F
was not found on this server. That’s all we know.