This has been working fine for years go here
https://www.linuxupdate.co.uk/2017/08/2 ... ailserver/

OMG!!!!!!!!!!
I have lost 5 night's sleep over this issue.

This now works for my external ip app to send me notifications
internet 10 - 5.7 default
localhost 80 - was 30
external ip app 100 - had to set to this to make it work.

this split me open...I've been looking for default domain for weeks.
gracias amigo!!