An interesting problem came up in the Microsoft public newsgroups this week. Richard posts:

We have a specific user requirement to auto accept meeting requests only from some selected organizers, but I don't see any choice in Rule Wizard for meeting requests. Does anyone have an idea, please?

Of course I have an idea. Begin with a rule using the conditions "from people or distribution list" and "uses the specified form", choosing the Meeting Request form under Application forms.

Since there is not an action to respond to meeting requests, you'll need to use a script to accept it. Outlook MVP Michal Bednarz offers this script, which you need to add to ThisOutlookSession before creating the rule.

This was tested in Outlook 2007 and should work in any version which supports the Run a Script action.

The Basic Code

Sub AutoAcceptMeetings(oRequest As MeetingItem)

If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If

Dim oAppt As AppointmentItem
Set oAppt = oRequest.GetAssociatedAppointment(True)

Dim oResponse
 Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.Display '.Send
End Sub

How to use

Open Outlook's VBA editor (Alt+F11), expand Microsoft Office Outlook Objects then double click on ThisOutlookSession. Type or paste the code into the module, then create the rule with the 'run script' Action and select this script

To decline a meeting, replace olMeetingAccepted with olMeetingDeclined:

Set oResponse = oAppt.Respond(olMeetingDeclined, True)

To Save with no response sent

To accept the meeting and add it to your calendar automatically, without sending a response, one of two options should work to suppress the response:

oResponse.Close (olDiscard)
or
oResponse.Close (olSave)
oResponse.Delete

The difference between the two is that olSave saves a draft of the acceptance (or decline) and if you don't delete it using the Delete line, a tentative appointment may be added to the calendar.

Sub AutoAcceptMeetings(oRequest As MeetingItem)

If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If

Dim oAppt As AppointmentItem
Set oAppt = oRequest.GetAssociatedAppointment(True)
Dim oResponse

Set oResponse = oAppt.Respond(olMeetingAccepted, True)
' creates response, saves to drafts without sending
oResponse.Close (olSave)
' deletes draft response
' if not deleted, may create tentative appt on calendar
oResponse.Delete
End Sub

Add a Category when the meeting is accepted

This version looks for the meeting acceptance message and adds a category to the meeting, allowing you to see at a glance if it was accepted.

Sub AutoAcceptMeetings(oRequest As MeetingItem)

If oRequest.MessageClass <> "IPM.Schedule.Meeting.Resp.Pos" Then
  Exit Sub
End If

Dim oAppt As AppointmentItem
Set oAppt = oRequest.GetAssociatedAppointment(True)

Debug.Print oAppt.Subject
oAppt.Categories = "Accepted"
oAppt.Save

End Sub

Move meeting to a new calendar after accepting

This run a script macro accepts the meeting then moves it to another calendar (a subfolder of the default calendar as written). See Working with VBA and non-default Outlook Folders for the methods needed to move it to other calendar folders.

Because moving a meeting adds Copy to the subject, it picks up the original subject and replaces the subject with it after the move.

Sub AutoAcceptMeetings(oRequest As MeetingItem)
If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If

Dim oAppt As AppointmentItem
Dim strSubject As String
Dim newCalFolder As Outlook.Folder
Dim apptMove As Object

Set oAppt = oRequest.GetAssociatedAppointment(True)
Dim oResponse
 Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.Send

strSubject = oAppt.Subject

Set newCalFolder = Session.GetDefaultFolder(olFolderCalendar).Folders("New")
Set apptMove = oAppt.Move(newCalFolder)

' use original subject and save
apptMove.Subject = strSubject
apptMove.Save
End Sub

Turn off Reminders

To turn reminders off on the meeting, add these lines to the code. It can either go right after the 'Set oAppt' line or before End Sub.

Appt.ReminderSet = False
Appt.Save

To Delete from the Inbox once processed

Add the following before End Sub:

oRequest.Delete

Apply rule to meetings scheduled for a specific day of the week

This edit uses the WeekDayName function to get the day of the week and automatically process the meeting. Use the full weekday name in the string.

dayWed = WeekdayName(Weekday(oAppt.Start))
If dayWed = "Wednesday" Then

Sub AutoAcceptMeetingsWed(oRequest As MeetingItem)

If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If
     
Dim oAppt As AppointmentItem
Set oAppt = oRequest.GetAssociatedAppointment(True)

dayWed = WeekdayName(Weekday(oAppt.Start))
   
If dayWed = "Wednesday" Then

Dim oResponse
 Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.Send

End If
End Sub

Accept Meetings during working hours

Use this macro to accept meetings only during your working hours. Any meetings before your working time or after your day ends, you be declined. Meetings during those times will be accepted.

Sub AcceptWorkingHours(oRequest As MeetingItem)
If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If
Dim oAppt As AppointmentItem
Dim oResponse
Set oAppt = oRequest.GetAssociatedAppointment(True)
meetingtime = Format(oAppt.Start, "h:mm:ss AM/PM")

If meetingtime < #8:45:00 AM# Or meetingtime > #6:45:00 PM# Then

Set oResponse = oAppt.Respond(olMeetingDeclined, True)
oResponse.Send
 
 Else
 
Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.Send
End If

oRequest.Close (olSave)
oRequest.Delete
End Sub

Decline if not enough lead time

This version of the macro will decline the meeting request if the meeting is on short notice. For this example, it is configured for 8 hours.

You can use either decimal points (Time + 0.333333) for the time difference or divide by hours or minutes: Time + 8/24 (or 480/1440).

Tip: If your lead time has many decimal places, the more you use, the more accurate the time, however, 5 to 6 decimal places should be accurate within a few seconds.

Sub LeadTime(oRequest As MeetingItem)
If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If
Dim oAppt As AppointmentItem
Dim oResponse
Set oAppt = oRequest.GetAssociatedAppointment(True)

meetingtime = Format(oAppt.Start, "h:mm:ss AM/PM")
Debug.Print Time, Time + 0.333333

If Time + 0.3333333 < meetingtime Then

Set oResponse = oAppt.Respond(olMeetingDeclined, True)
oResponse.sEnd
 
 Else
 
' delete these if you want to accept/decline yourself
Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.sEnd
End If

oRequest.Close (olSave)
oRequest.Delete
End Sub

Check Free/Busy before accepting

Steve wanted to know how to decline if there was a conflict. For this we need to check Free/Busy. Checking the Free/Busy is actually fairly easy and the code we need is at Recipient.FreeBusy Method.

Set yourself as a Recipient, using your email address, display name, or alias:

Set myAcct = Session.CreateRecipient("alias@slipstick.com")

Then get your Free/Busy string:

myFB = myAcct.FreeBusy(oAppt.Start, 5, False)

You need a date to check, and we'll use the appointment start date. The Free/Busy string begins at midnight on this date.

The next value is how many minutes are in each Free/Busy "period" represented by the myFB string. After much trial and error, I've decided that 5 minutes is probably the best value, since it's the smallest time period displayed on the calendar.

The final value is True or False (if you leave it blank, it's False). False tells Outlook to either return 0 for Free (and Working elsewhere in Outlook 2013) and 1 for "not free". True returns values specific to the Show time as setting.

Next, you need to know how many time periods are between midnight and the appointment time (there are 288 5 minutes periods each day):

i = (TimeValue(oAppt.Start) * 288)

Use that value to create a string of the periods the appointment covers. If you want to build in some downtime between appointments, subtract from i before calculating ( i - 2 gives 10 min between appointments) and add the same value to the duration calculation.

test = Mid(myFB, i, oAppt.Duration / 5)

test = Mid(myFB, i-2, (oAppt.Duration / 5)+2) starts 2 periods before the start time, or in my example, leaves 10 min between the last appointment and this one.

Finally, we use InStr to look for a match within the substring that covers our appointment period. If the string contains a 1, the appointment should be declined:

If InStr(1, test, "1") Then

To help you understand the code (and check my calculations), I left my Debug.Print code in. Open the Immediate windows in the VB Editor using Ctrl+G or select it from the View menu to see the results. Those 0, 1, and 2's each represent a 5 minute block of time beginning at 12:00 AM on that date.

Sub CheckFreeBusy(oRequest As MeetingItem)
If oRequest.MessageClass <> "IPM.Schedule.Meeting.Request" Then
  Exit Sub
End If
 
Dim oAppt As AppointmentItem
Set oAppt = oRequest.GetAssociatedAppointment(True)

Dim myAcct As Outlook.Recipient
Dim myFB As String

Set myAcct = Session.CreateRecipient("alias@slipstick.com")

Debug.Print oAppt.Duration
Debug.Print "Time: " & TimeValue(oAppt.Start)
Debug.Print "periods before appt: " & TimeValue(oAppt.Start) * 288
Debug.Print oAppt.Start

myFB = myAcct.FreeBusy(oAppt.Start, 5, False)

Debug.Print myFB

Dim oResponse
Dim i As Long
Dim test As String

i = (TimeValue(oAppt.Start) * 288)
test = Mid(myFB, i - 2, (oAppt.Duration / 5) + 2)

Debug.Print "String to check: " & test

If InStr(1, test, "1") Then
 Set oResponse = oAppt.Respond(olMeetingDeclined, True)
 oResponse.Display
 
 Else
  Set oResponse = oAppt.Respond(olMeetingAccepted, True)
 oResponse.Display
End If
End Sub

If you want to check for specific values or consider tentative appointments as Free, you can change If InStr(1, test, "1") Then to use different values. Use If InStr(1, test, "2") or InStr(1, test, "3") Then to check for Busy and Out of Office.

How to use the macros on this page

First: You need to have macro security set to the lowest setting, Enable all macros during testing. The macros will not work with the top two options that disable all macros or unsigned macros. You could choose the option Notification for all macros, then accept it each time you restart Outlook, however, because it's somewhat hard to sneak macros into Outlook (unlike in Word and Excel), allowing all macros is safe, especially during the testing phase. You can sign the macro when it is finished and change the macro security to notify.

To check your macro security in Outlook 2010 and newer, go to File, Options, Trust Center and open Trust Center Settings, and change the Macro Settings. In Outlook 2007 and older, look at Tools, Macro Security.

After you test the macro and see that it works, you can either leave macro security set to low or sign the macro.

The macros on this page should be placed in a module.

Open the VBA Editor by pressing Alt+F11 on your keyboard.

To put the code in a module:

1. Right click on Project1 and choose Insert > Module
2. Copy and paste the macro into the new module.

More information as well as screenshots are at How to use the VBA Editor