Outlook Meeting Requests Don't Go to Calendar

[Jenn]

I have a user who is having trouble with meeting requests. If someone from
within our office sends her a meeting request - she accepts it and it goes to
her calendar. However, if someone from outside our office sends her a
meeting request - she accepts it but it never makes it to her calendar. Has
anyone else had this issue or know what we need to change to fix it?

Thanks!