Hello all,

We recently upgraded some of our employees to Office 365 and we've been experience a calendar sharing issue.

When someone recently upgraded attempts to share their calendar with someone also on Office 365/2013 they get an error saying "This sharing message is not valid. All action buttons have been disabled. (sender not verified)"

One weird detail is when the calendar in 2013 is trying to share with other 2013 users it fails. When it tries to share with Outlook 2007 users it fails. Except for a couple random users on 2007.

Running Exchange Server 2007 as well so maybe that is the issue?

Some methods I've tried, from reading other articles on this is:

1. 1) Outlook in safe mode
2. 2) Recreate Outlook Profile
3. 3) Permission changes on the calendar in question
4. 4) Install 365 on a separate PC

Any ideas?

Thanks 

Hi,

Based on the description, it doesn't seem like a pure Outlook client thing.

I've seen a similar issue in this thread, AD is also involved.

You may need to open up the user's Active Directory account in AD users and computers and put their email address in the email filed on the general tab of the users properties page.

Regards,

Melon Chen
TechNet Community Su

We checked the AD properties of the user and the email is already filled in correctly so that was no help unfortunately.

Forgot to mention that was something we already checked.

Hi,

Based on the description, it doesn't seem like a pure Outlook client thing.

I've seen a similar issue, AD is also involved.

You may need to open up the user's Active Directory account in AD users and computers and put their email address in the email filed on the general tab of the users properties page.

Regards,

Melon Chen
TechNet Community Su

We are having the same issue - our 365 user has shared a cal with 6-7 other people and 3 of them are getting the "This sharing message is not valid. All action buttons have been disabled." Then a bit below is the "Sender not verified" message.

Email address IS on the AD General tab, and they are all on the same server, Exchange 2007, mix of 2010 and 2013.

We are having the same issue - our 365 user has shared a cal with 6-7 other people and 3 of them are getting the "This sharing message is not valid. All action buttons have been disabled." Then a bit below is the "Sender not verified" message.

Email address IS on the AD General tab, and they are all on the same server, Exchange 2007, mix of 2010 and 2013.

We found something odd with cache mode.

If you disable cache mode then there is no error. Doesn't really resolve the issue but is a workaround....sort of

We've discussed the cache mode issue with Microsoft and there "Engineers" and they had no answer.

Side Note: if you send the request and get the sender not verified and then go to open a shared calendar you can actually access the calendar. Unfortunately the initial share request replies with a not verified message. Still work though.

We are having the same issue - our 365 user has shared a cal with 6-7 other people and 3 of them are getting the "This sharing message is not valid. All action buttons have been disabled." Then a bit below is the "Sender not verified" message.

Email address IS on the AD General tab, and they are all on the same server, Exchange 2007, mix of 2010 and 2013.

We found something odd with cache mode.

If you disable cache mode then there is no error. Doesn't really resolve the issue but is a workaround....sort of

We've discussed the cache mode issue with Microsoft and there "Engineers" and they had no answer.

Side Note: if you send the request and get the sender not verified and then go to open a shared calendar you can actually access the calendar. Unfortunately the initial share request replies with a not verified message. Still work though.