This site did not show evidence of storing passwords in plaintext.
This site does allow secured connections (https)
This site did show a clear way to unsubscribe from their emails
This site does verify your email address.
Membership Emails
Below is a sample of the emails you can expect to receive when signed up to Wallpapers.
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https://wallpapers.io/verify/account/pPLY0W25iy7vOpGMJnXxLIMunn5o6QQZ8cvZat24WJwl3dYj9oiiRhPULOMegVtDq6Y4fSvsrxWOn6wTbhcJqFAAFDdnuS7i771z