Outlook 2007 and Exchange 2013 not a real good combination

exchange 2013 and outlook 2007 is a interrested thing

outlook 2007 SP3 is supported with with April 2014 Public update KB 2863811
See https://technet.microsoft.com/library/dn803988(v=office.14).aspx

For you as a System or Exchange administrator or Consultant you might consider some things before migrating to exchange 2013.

You can't share your calendar in Outlook 2007
When you use microsoft office Outlook 2007 to share your calendar, you receive the following error message:

Error while preparing to send sharing message.

Also, if you try to check the permissions on the calendar, you may receive the following error message:

An error occurred when setting schedule permissions.

Solotion Microsoft: Using owa

It works for share the calendar and you can set editor calendar permissies. All other permissions are not availible

• Accessrights Missing
  None
  Owner
  PublishingEditor
  PublishingAuthor
  Author
  NonEditingAuthor
  Reviewer
  Contributor

  With powershell you can set the permissions

Add-MailboxFolderPermission –identity (username+':\calendar') –user testuser –Accessrights PublishingEditor

Better solution

Upgrade your Outlook Client to 2010 or 2013