You need to have a good email list on website/blog/forum that related to web design & development, web hosting...from the, you start send email marketing via newsletter, that will help you to get sales for your hosting services.
I have 12 years of expertise of server setup for email marketing, we need to setup server as per below mentioned points
1. Install Pmta server with IP and Domain rotation for mailing.
2. Create all the mail authentication records SPF, DKIM, DMARC and rDNS.
3. Will give 10/10 score on mail tester.
4. Mails landing in inbox depends upon the ip and domain reputation and The content you are sending.
5. Install Mailwizz or any other application for mailing.
Requirements as per -
1. Server with 8gb ram and multiple ips
2. Domain names
3. Domain registrar details
4. Server provider Details to create rdns
Note: Most important clean and verified mail list.