Inorder for our system admin to complete the smtp server installation on your linux vps, we need your vps provider login details along with your domain registrar login details where the domain for your vps has been registered.
We will set the name servers on your domain to point to the vps and fetch the server root password to do the installation by logging into your vps provider and also setup the reverse dns on your vps provider.
But some clients who are new to our business may have the lack of trust in giving those login details , and that is okay we can understand.
If you are uncomforatable with giving login details, we can provide videos for you to set the name servers on your domain registrar and also to fetch the root password and set the rdns on your vps provider so that you can do it by yourself by referring the video.
If you want us to do the entire thing for you , we will do it and after we deliver your server, you can change the password of your domain and vps login.