Hi

I have a colleague who is trying to send a meeting invite to all members in a distribution list, but some of the staff members that are required to attend are  shown as optional.

Does anyone know how  this happens and how to recify it?

Many thanks

J.

Hi,

Please let the colleague organize the meeting on OWA, does the issue persist? Or it only happens when sending the meeting from Outlook?

For these attendees who display as optional, do they use the account/calendar on other devices? Like a phone or a tablet? This could be the cause in this scenario. A sample.

I also suggest you try sending the meeting request by expanding the distribution list; if it helps, here is an explanation why we suggest this:

Please understand that Meeting request in question were send Distribution List without expanding it. Outlook consider Distribution List in Meeting request as a single Attendee. When Outlook receives a meeting acceptance, the sender of the acceptance is compared to the recipients listed in the meeting item attendees. If that recipient is not listed as it was send to Distribution list, it is assumed to be "optional" and added to the list of attendees.

Regards,

Melon Chen
TechNet Community Su