Sometime when I go to /admin I'm redirected to my user admin profile. Bug or feature?

Hello, each time I set SMTP parameters, emails work (email test or email confirmation) then few minutes later a "reset" happend and when I request something involving emails I get connect ECONNREFUSED 127.0.0.1:587 {"errno":"ECONNREFUSED","code":"ESOCKET","syscall":"connect","address":"127.0.0.1","port":587,"command":"CONN"}