This article provides you with some information regarding the Plesk website statuses: Suspended, Disabled, and Active.
If you want to shut down a site for maintenance and let your visitors know that it is temporarily unavailable, you can suspend the website so that it will not open in browsers (Websites & Domains > domain name > the Suspend button).
You can customize the error page using the Error Documents in your Virtual Directory
Note: The link Edit error page is displayed only if your hosting plan provides the option to customize web server error documents (the Custom error documents is On in the domain settings in Websites & Domains > domain name > Hosting Settings).
If you stop maintaining a website, you can disable it using Websites & Domains > domain name > the Disable button.
Disabled websites stop being hosted on the server: They are excluded from the web server configuration. However, the physical directories and files of disabled sites can be accessed by FTP clients and File Manager.
The hosting services such as mail will be unavailable.
To bring the website back online, use Websites & Domains > domain name > the Activate button. The website will start working as usual.