I had a running instance of MIAB on Ubuntu 14.04. It ran out and I forgot to do a backup.
Today I installed 16.04 upgraded it to 18.04 and installed MIAB again I am getting the following error:
Glue and DNS records are setup I reran the script several times and sometimes I get the error in the screenshot and sometimes that it can’t resolve my domain.
root@box:~# sudo mailinabox
sudo: unable to resolve host box.onlinemail.ovh: Resource temporarily unavailable
What is the problem with my setup?
Try a fresh install of 18.04 LTS. Don’t use 16.04 then upgrade.
Well I would but non of the providers support it. I have rented to vps and couldn’t select 18.04 support said “google how to upgrade yourself” and they simply don’t care. I don’t want to run it constantly I just need access to my old mail accounts in order to change the mails, is there a simpler way do to that?
Both azure and DigitalOcean work well with MIAB and support 18.04. Try DO: https://m.do.co/c/93604d2ec646
If your vitrualization is OpenVZ it will not support Ubuntu 18.04 because of the old kernal that is used. You need to use a VPS which uses KVM virtualization. There are MANY good providers out there including (but not limited to)
BuyVM, Lunanode, Time4VPS, Aruba Cloud, Digital Ocean, Linode, AlphaVPS …
Could you please elaborate more … there likely is a way, just need to know EXACTLY what you are meaning. 
Used your affiliate link and now managed to get MIAB running on my old domain. I can thereby access the old accounts. SOLVED
Hope the affiliate link helped! Did you get the $50 credit as well?