I have a problem with a pair of Macs, one is ours, one external.

Our Mac is using OS X Mavericks and MS Outlook 2011, in conjunction with Exchange Server. The Mac outside is using OS X Mountain Lion and a hosted mail account, using the inbuilt Mail and Calendar applications and an POP/SMTP mail account with the internet provider.

When an invitation is sent from our Mac, the external Mac receives the invitation and accepts the appointment, with reply. The appointment is entered into the calendar on that Mac.

However, we do not receive a confirmation email and the status of the person in the meeting plan is still set to not replied.

I just tried this with my GMail account on the Mac and I got a reply back, but that could be a GMail server feature, like Exchange, which automatically generates the reply.

Is this a problem with POP accounts or is there some configuration issue?

I think I might have the answer...

With Outlook, because it is integrated, when you select to put the appointment in the calendar, it automatically asks if you want to send a confirmation.

With OS X Mail and Calendar, opening the appointment and putting it in the calendar does not send any form of confirmation. You have to then explicitly go into Calendar, open the appointment and select Accept, at which point it sends out a reply. (That is what happened with my first attempt, I opened the appointment straight away and saw the accepted dropdown and clicked on it, that is why I received the confirmation email straight away. I then sent another appointment, opened it in Calendar and I didn't get a confirmation for 30 minutes. I then went into the appointment in Calendar and clicked the Accept drop down (Accept was already selected!?!).)

So, it seems a little confusing, that the appointment is "accepted" automatically in Calendar, but not "accepted", in that Calendar doesn't send out the confirmation until you actually click on the drop down saying that the appointment is already accepted!

Tried it again today and I was getting automaic replies from my GMail account through Mail/Calendar.

I then deleted the account and set it up as POP Mail for GMail, no link to GMail Calendar. Now I don't receive a confirmation when I send myself an invitation (work account to GMail). The appointment appears in Calendar and it doesn't give me the option of accepting or rejecting the appointment. I think this is where the problem lies. Without a "server" based calendar no replies are being sent.