SharePoint 2013 open Access request link is missing

The practice of opening access requests for SharePoint 2013 is simple, such as http://www.cnblogs.com/jianyus/archive/2014/06/21/3799386.html this blog, But a lot of I do not have the corresponding link (I am here environment is sharepoint2013 SP1),

I've been searching the internet for a long time. Prompts to configure outgoing e-mail settings.

The steps are as follows:

Go to Central Administration-"System settings-" Configure outgoing e-mail settings

Configure outgoing e-mail and then switch to permissions to see:

The e-mail address must be entered here.

Note that access requests are turned on, but access requests and invitation links do not appear. The link will only appear if someone has sent an access request.

The "Access requests and invitations" link will not appear after the request is sent, click Access requests and invitations

You see this, the back of what is needless to say.

SharePoint 2013 open Access request link is missing