Have 3 independent servers (America, Europe, Asia) confirm if your website is really down.
is https://www.website-down.com/https%3A%2F%2Fdownloads.skylum.com%2Fluminar4%2Finstaller%2Fwin%2FLuminar4Setup.exe%3Futm_source%3Demail working?
https://www.website-down.com/https%3A%2F%2Fdownloads.skylum.com%2Fluminar4%2Finstaller%2Fwin%2FLuminar4Setup.exe%3Futm_source%3DemailYOUR WEBSITE IS UP