Office365: POP and IMAP clients receive OWA links for calendar invitations
As you may know, Office 365 supports a number of different client protocols, including POP and IMAP and a variety of POP and IMAP clients. By default, POP or IMAP clients will be configured to use Outlook Web App (OWA) for handling calendar invitations. When these clients receive a meeting request, within the body of the invite is a link. Clicking on the link allows the user to open their mailbox via OWA so they can accept or decline the request.
If you are using a POP or IMAP client that is capable of handling ICAL messages, you may want to change your configuration settings so that you can get a better experience.
You can configure – on a per-mailbox basis – how POP and IMAP clients receive calendar appointments. Get-CASMailbox can be used to view your current settings.
Get-CASMAILBOX –identity <NAME> | fl name,*pop*,*imap*
Name : administrator
ExternalPopSettings :
InternalPopSettings :
PopEnabled : True
PopUseProtocolDefaults : True
PopMessagesRetrievalMimeFormat : BestBodyFormat
PopEnableExactRFC822Size : False
PopSuppressReadReceipt : False
PopForceICalForCalendarRetrievalOption : False
ExternalImapSettings :
InternalImapSettings :
ImapEnabled : True
ImapUseProtocolDefaults : True
ImapMessagesRetrievalMimeFormat : BestBodyFormat
ImapEnableExactRFC822Size : False
ImapSuppressReadReceipt : False
ImapForceICalForCalendarRetrievalOption : False
In the above output, you can see two attributes that you need to set to True to enable iCAL support. The *ICALForCalendarRetrievalOption specifies that the client should be provided calendar appointments that are in ICAL format.
Also note the *UseProtocolDefaults attributes. These must be set to False in order for any changes to *ICALForCalendarRetrievalOption to take effect. You can use Set-CASMailbox to change these settings:
Set-CASMailbox –identity <NAME> –PopUseProtocolDefaults:$FALSE –ImapUseProtocolDefaults:$FALSE –PopForceICalForCalendarRetrievalOption:$TRUE –ImapForceICalForCalendarRetrievalOption:$TRUE
Name : administrator
ExternalPopSettings :
InternalPopSettings :
PopEnabled : True
PopUseProtocolDefaults : False
PopMessagesRetrievalMimeFormat : BestBodyFormat
PopEnableExactRFC822Size : False
PopSuppressReadReceipt : False
PopForceICalForCalendarRetrievalOption : True
ExternalImapSettings :
InternalImapSettings :
ImapEnabled : True
ImapUseProtocolDefaults : False
ImapMessagesRetrievalMimeFormat : BestBodyFormat
ImapEnableExactRFC822Size : False
ImapSuppressReadReceipt : False
ImapForceICalForCalendarRetrievalOption : True
The settings described here are per-mailbox settings. There is no global setting to change the default for the entire tenant. There is also no method to adjust the settings per-client.
Comments
Anonymous
January 01, 2003
@Rad:
Excellent - i'm glad this helped.
TIMMCMICAnonymous
January 01, 2003
@SWILSONZ
NP - if you do not find what you need let us know.
TIMMCMICAnonymous
January 01, 2003
@JurgenO
Your administrator needs to do this for you.
TimAnonymous
January 01, 2003
@SWILSONZ
You have to log into your Exchange Online / Office 365 tenant via powershell.
Several references can be found online.
TIMMCMICAnonymous
January 01, 2003
@Daniel...
I'm not familiar with the application you are using so I cannot advise.
TIMMCMICAnonymous
January 01, 2003
@NeCoMuk
Would you care to contribute something.meaningful?
TimmcmicAnonymous
January 01, 2003
@Pete :
I might add a suggestion to this. When doing bulk operations like this depending on the tenant size you'll end up having powershell throttling kick in. I would commend the following to assist in avoiding this:
Get-Mailbox -ResultSize unlimited | Set-CASMailbox –PopUseProtocolDefaults:$FALSE –ImapUseProtocolDefaults:$FALSE –PopForceICalForCalendarRetrievalOption:$TRUE –ImapForceICalForCalendarRetrievalOption:$TRUE -verbose ; start-sleep -m 500
The -verbose allows us to see that the command continues to be processing and the start-sleep puts a 500 ms delay inbetween each set.
You might also consider doing the get completely different from the set.
Get-mailbox -resultsize unlimited | export-CSV
$users=import-CSV
foreach $users | Set-CASMailbox -identity $_.alias –PopUseProtocolDefaults:$FALSE –ImapUseProtocolDefaults:$FALSE –PopForceICalForCalendarRetrievalOption:$TRUE –ImapForceICalForCalendarRetrievalOption:$TRUE -verbose ; start-sleep -m 500
TIMMCMICAnonymous
January 01, 2003
@A Magliocco:
You would need to use remote powershell for Office 365. Several references can be found online.
TIMMCMICAnonymous
November 19, 2013
Thanks, I've been looking for this for a while now in the Office 365 forums.Anonymous
May 08, 2014
Will enabling this resolve issues pertaining to the calendar.app (OS X 10.9.2)? Assistance greatly appreciated.Anonymous
May 29, 2014
Using Outlook 2013 sending invites and only affects when recipient using POP3 in our case. A suggestion above had helped. Thank you!Anonymous
July 15, 2014
I came across this site when searching for the OWA link in an Outlook pop account. Could you please clarify whether this setting change needs to be undertaken by an administrator on the host, or is it a setting I as the end-user am able to make?Anonymous
November 07, 2014
The comment has been removedAnonymous
November 07, 2014
try this for all mailboxes
Get-Mailbox -ResultSize unlimited | Set-CASMailbox –PopUseProtocolDefaults:$FALSE –ImapUseProtocolDefaults:$FALSE –PopForceICalForCalendarRetrievalOption:$TRUE –ImapForceICalForCalendarRetrievalOption:$TRUEAnonymous
November 07, 2014
Thanks this looks like it might help. We are on office 365. What do I import to get these commands. Get_CasMailbox, and Set-CasMailbox are not valid commands on our AD server.Anonymous
November 07, 2014
@TIMMCMIC
Thanks, a solution and a direction!Anonymous
May 11, 2015
This is great information but for us uninformed folks where does this code go?Anonymous
April 05, 2016
does this command work for kiosk plans?- Anonymous
May 08, 2016
Yes - this should work with Kiosk plans.
- Anonymous