If your not receiving 'Invites' from another Outlook client then you should check the following:

Junk Folder

1. Click the "Home" tab and then click "Junk" in the Delete group to load your Junk folder.
2. Scroll through your Junk folder to see whether meeting invitations have been inadvertently directed there.
3. Click and drag any misplaced meeting invitations into the "Inbox" folder to move them there.
4. Add the sender's email address or their entire domain to the Safe Senders group. To do this, start by clicking the "Home" tab.
5. Click "Junk" in the Delete group, click "Junk Email Options" and then click "Add" on the Safe Senders tab.
6. Enter the sender's email address or the entire domain in the "Enter An Email Address Or Internet Domain To Be Added To The List" box. If the email was sent by person@work.com, for example, you can enter only that email address or you can enter "@work.com" without quotation marks to allow all email addresses from that domain. If you want to mark as safe all of the senders in your Contacts directory, click the "Also trust emails from my contacts" check box on the Safe Senders tab.
7. Click "OK" when you're finished.

Rules

1. Click the "File" tab, then click "Manage Rules & Alerts" to load the Rules and Alerts settings screen. On this screen you will see a list of rules designed to filter your emails into folders upon arrival.
2. Scroll through the existing rules and click them to examine whether one is configured to send meeting invitations to an undesired location. More often than not, rules are created based on the email address of the sender.
3. Delete any unwanted rules that might be filtering meeting invitations to undesired locations. To delete a rule, click the rule to select it, click the "Delete" button and then click "OK" to confirm that you want to remove the rule.

Automatic Replies

1. Click the "File" tab, then click "Options" on the menu on the left side of the screen.
2. Click "Calendar," scroll down and click "Auto Accept/Decline" in the Automatic Accept or Decline section.
3. Remove the check mark from the "Automatically accept meeting request and remove canceled meetings" check box. When this box is checked, Outlook automatically accepts meeting invitations that your calendar indicates you are available to attend. The person who sent you the request receives an email confirmation, but you may not be notified of the arrival of the invitation email itself.
4. Click "OK" to exit the window, then click "OK" again to exit the Options screen.

If your still not receiving invites then its possible that either the invites are not being received, or that they are being intercepted by another client (such as a mobile device). If your using a GEN Email service then login via the web and make sure that the invite exists in the inbox and is properly addressed and formed.