This is actually a pretty common issue and it’s usually happening on the sending side rather than yours.
When a domain has previously had a bounce, spam complaint, or delivery issue with the email provider n8n uses, that address or domain can end up on a suppression list. Once that happens, emails simply never get sent out , which is why you’re not seeing anything in spam or quarantine. The message never leaves n8n’s side.
Since registering with a different email worked immediately, that confirms the issue is specific to your domain and not your mail server or filters.
Best move here is to contact n8n support directly at support@n8n.io and mention exactly what you’ve told us , that the verification email never arrives for your company domain but works fine with other addresses. Ask them specifically to check if dedi.it or info@dedi.it is on a suppression list with their email provider and request it to be removed.
In the meantime, if you need to get moving quickly, you could register using a personal email or a Gmail address just to get access, then update your account email once the suppression issue is resolved.
Let me know if you hear back from support, would be good to know what the root cause was.