Cannot react on a meeting invitation sent to an Exchange email group

My eM client is configured to an Exchange account. When someone sends an meeting invitation to an Exchange email group I am in, I get the invitation and can see it, but there is no Attend or Decline button. For the same account and meeting invitation, Outlook gives me the option to attend or decline the meeting. What can I do to get this feature in eM client as well?

I saw something like this before where the meeting invite was not sent to your email address (the one that the account calendar is setup as) and so eM Client did not offer the accept or decline option.