DMARC Blocking.

My wife and I are both experiencing undelivered mail from a Centurylink email address on iphones, Samsung tablets and PC's using MS outlook for our Xfinity mail addresses.

The error message is DM000001

Thank you for your time today, @Hillmac. Have you had a chance to reach out to our Customer Security Assurance team?-Richard

Got it , user_cdb4b4! Besides the calendar invites, is your wife having any issues sending or receiving emails? Does she access her email via the web portal [connect.xfinity.com] or through a third-party app (Outlook, Apple Mail, etc.)?

No she is not. 

Crazy part is if I email her directly she still gets the email but I get this error message. 

But she is not getting the invites sent as a result of an invite to an activity or appointment via my calendar. 

And again, this never hairbrush before.  It is a new occurrence. 

She accesses it via either  outlook or Samsung's email app.

Understood @user_cdb4b4, and yeah, that is odd. Unfortunately, with this Outlook calendar invite issue, we're limited on what we can do to troubleshoot this, since your wife is successfully able to send and receive from her Xfinity email. 

Have you tried reconfiguring your wife's Xfinity email with Outlook or Samsung? You can do so following the instructions provided in this link Set up your Xfinity Email address with an email program - Xfinity Support. Also, have you tried reaching out to Outlook support? 

The issue is due to Comcast from all my research. 

It's not a problem with outlook according to Outlook. I already went that route.

It's your server that is blocking and sending the error. As I said it is stopping my calendar invites from being emailed to my wife's calendar using Samsung Calendar not Outlook's.