I'm looking to add custom message on Access Denied page in SharePoint 2013 and need to add Site Admin information as each and every site's having different site owner, so message should come up with individual site owner information to whom the request is redirected for further processing.
Based on my research, we could not show site Administrator/Owner information on Access Denied page SharePoint 2013, it is by design.
However, we can enter site Administrator/Owner email in the "Send all access requests to the following e-mail address" textbox. When someone need to access the site, you can send a message to this site Administrator/Owner.
Please follow the steps:
1.Sign in the site collection as a site administrator
2.Go to the Site Settings page, click Site permissions
3.On the Site Permissions page, click "Access Request Settings" on the PERMISSIONS tab
4.On the Access Request Settings windows, select "Allow access requests" checkbox and enter the email of the site Administrator/Owner in the "Send all access requests to the following email address" textbox.
5.When someone wants to access the site, the user can send an access request to the site administrator.