My ISPConfog 18.104.22.168 was working just fine on earlier location (after great help of you guys), but now on new location & ISP and router (Buffalo ADSL) I have ended up trouble on mail-server. - All ISPConfig servicies green / running w/o problems (as I use them) - Fetchmail OK (from firstname.lastname@example.org to email@example.com) - Sending mail with roundcube firstname.lastname@example.org => email@example.com OK - Sending mail with roundcube firstname.lastname@example.org => email@example.com OK - receiving from other email to firstname.lastname@example.org gives trouble (copied from email delayed alarm) Code: <email@example.com>: connect to example.com[83.zzz.yyy.zz]:25: Connection timed out As I have 2 routers in my system, I have made server1 as DMZ in Buffalo. Also portscan shows that needed ports on example.com are open (21, 22,) 25 (, 53 etc.). Also individual port-forward sis not change situation better. What to check next - thanks for advice already now.