Bookmark Redirection Is Supported Even When Chatter Is Disabled
The ability to redirect bookmarks is important to implementing My Domain. When you create a subdomain, let’s say companydomain.my.salesforce.com, you want to ensure that all users use the subdomain URL rather than the instance URL. If users have bookmarks to the instance URL, like na1.my.salesforce.com, you can now redirect them to your subdomain, companydomain.my.salesforce.com.
If you’re planning to enable MyDomain and don’t have Chatter enabled, contact Salesforce to enable this feature.