IP of my box is in a blacklist

Hi, just discovered the IP of my box is in a couple of blacklists.
Provider (linode) offered to change it.
I’m wondering:
Apart from changing the IP in Godaddy control panel, what I have to do in my box?
Do I have to reinstall it again? Need to start again from a fresh Ubuntu installation?
Which command string should I use?
Am I going to loose messages users and configuration existing or is a straight process?
Sorry but it took me ages to get it working as I want, and I’m not sure if doing the process again is gonna be a success again :smile: Can you please help me, to make sure us gonna be done properly.
Thanks

Just run mailinabox, which runs the setup script again, and you should be fine.