We are having a similar issue.

We are running SmartMail 16.3.6821.

Ally and Alex have Outlook 2013 and calendars are shared using Sharepoint connection.

Mike has an iPhone with ActiveSync connected to his calendar.

Frequently Ally or Alex will make an appointment and the appointment will keep duplicating.  If Mike makes an appointment there are no issues.  I can't verify that it only happens when Ally and Alex make appointments, but it only happens when someone makes the appointment in Outlook.

Any help would be greatly appreciated.

-Ben

Hello Paul/Ben, I believe your next step would involve getting on to the latest minor release of SM 16 first. Once there, have the user remove the account sync profiles from Outlook and anywhere else they have it set up, then log in to their account via webmail and go to Settings>Connectivity>Synchronized Devices and remove the entries associated with those mail clients. Finally, add the accounts back in to the devices one at a time, allowing sufficient time for the initial sync. Once all of that is done, go ahead and try this process again to see if it persists. Please let me know how it goes!

We're having this same issue. Opened a ticket today.

Hello everyone! Michael Breines directed me to this thread today as he noticed he's not the only one reporting this issue, and thought you all might benefit from a status update! So, from our troubleshooting so far we've found out that the Add invites as tentative appointments can cause meeting duplication in Outlook 2016. This doesn't happen all the time, but it is an issue we've seen intermittently and are troubleshooting further. Development believes they have the root cause narrowed down, but will need to continue testing to confirm before they can release a fix build for this unfortunately. Intermittent issues are always the worst!

Disabling the Add invites as tentative appointments can resolve these issues, but introduces problems accepting invites on other third party applications like the Blackberry+ suite. At least in that scenario we have narrowed down the accept issues to a display problem in the Blackberry+ suite. The workaround involves enabling the Add invites as tentative appointments toggle, but this reintroduces the issues outlined above. 

We're digging into this further, and hope to have feedback/resolution soon. I will follow up here when we know more as well. Thanks for reading, and have a great rest of your week!

Thanks @kyle for the post back.

Yes we use Blackberry Hub+ suite on a lot of Android devices, but we also see the duplication on accounts that only use the Samsung email application too. 

I imagine that the issue here is some sort of EAS collisions that are happening with the EAS account on the mobile device and the EAS account in Outlook. Maybe the order of devices connected takes precedence. Maybe one device is putting the appointment on the calendar first and that makes the duplicate vs. the Smater Mail server putting it on the calendar first as tentative before the clients can read the incoming appointment? Something like that. (spitballing here)

in any event. It'd be incredible to solve the duplicate events in Outlook soon with EAS considering that MAPI (for Outlook) is still a while out. 

Much appreciated for the deep dive on this.

Side note: We're on v100 (17.x) and seeing the problem... but this has been happening since 15.x and apparently per @ben and @paul above also on 16.x.

My customers have also encountered duplicate calendar entries.  I narrowed it down to a problem with EAS and Outlook vs. Smartphone's syncing.  I hadn't thought about doing some tests using tentative appointments.  Troubleshooting via the logs was incredibly hard, so gave up.  Looking forward to MAPI.

Hello everyone. Just a quick update for you on this. I've received word that this duplication issue is still on our list, but has not yet been resolved. I would anticipate this getting looked at again tentatively next or following release. I'll try to get another update posted here when I hear back.

Update on this issue:  I updated to the latest SM 16.x version and started to delete everyone's Sharepoint lists and then re-adding them and immediately had problems with the Sharepoint sync and making more duplicates.  I had to go through and delete everyone's Sharepoint connection, go through everyone's calendars and remove all the duplicate meetings (literally took me two days to do that), then go a re-attach everyone's Sharepoint connection.  We might use it a little different than everyone else, we have our sales administrators make everyone's appointment so we have about five people that have all our sales schedules on their Outlook, the the sales people mainly access their calendars on their cell phones.  So far everything has been good and I made sure to let everyone know if they see any errors when adding/deleting/editing schedules to let me know.  Been three days without any issues.

Thats great to hear Ben! I do know that the Sharepoint integration has some intermittent issues in Outlook due to the size of the lists being synchronized. As such, I recommend getting on to our latest version if possible as it includes new support for larger lists. I hope you continue to see smooth sailing!

Seeing a strange trend. Sometimes the duplicate events show in Outlook. sometimes in the Samsung mobile device. Something strange with EAS integration indeed. Looking forward to a fix!

I am having duplication with the last build (May 9th 7068).  If I put an appointment on my calendar in Outlook 365 I get repeated duplicates on my Android phone using MS Exchange.  This all started after I installed the latest build.

Have a lot of customers which complains about that too, presently running with Build 7082

I updated to 7082. It did not fix the problem. 

Updated to 7090.  Still having the problem.  Are you guys aware of this issue?  Are we working on it???

Hello Bob.  I would recommend opening up a support ticket so that we can take a look into this.  Thanks!

Hi Rod,

I've got the same problem of duplicates (build 7090). 

I have got an open ticket about it and other bugs ;)

Hello all.  This build fixes the Sharepoint duplication issue.

Hi Rod,

Why such important fixes are not public? I mean it needs digging in community forums to find a post with a link to it, while the smartermail download page still propose a build that has a broken spool overview... (fixed in 7093 but again, only found it in a community thread)

There's also no changelog with these custom builds, so yes we know what is particularly fixed/changed but are not aware of other changes while applying it.

I really don't get it :'(

We're having trouble understanding what issue has been resolved and how to solve it.

Take for example one sample account:

In the web interface and outlook (EAS) we don't see duplicate events.

... however in Samsung Android 9 tablet calendar (also EAS) some events are duplicated

Michael, are you using at all the SharePoint feature ? (add to outlook menu option in webmail)

The fix in build 7117 seems to address a problem with SharePoint.

But if you're seeing issue and you don't use this feature, maybe the duplicates events problem is more global ?

We applied latest build and notified our customers having duplicate events, but we don't have confirmation yet that the problem is solved on their side...

No we're not using Sharepoint. Just EAS connected devices: Outlook and mobile

Looks like it's fixed - builds 7153 and 7236 have been good.

Hum. We're on Build 7242 and I just got a duplicated appointment in Outlook 2016. It was sent from another user also on Outlook 2016. 

Our calendar settings (Settings | Calendar Settings in SM) are set to:

"Add invites as tentative appointments"  

And if we have that setting toggled on, we get duplicated appointments often.

If we have it off, then some applications on some devices (namely our devices using Blackberry's really functional HUB software on Android) won't let you accept calendar appointments.

Bert Garrett-Tuck  do you have the "Add invites as tentative appointments"  on or off?

@Michael Breines 

I've been able to create a duplicate - without intending to :-)

Invites as tentative appointments is ON in the settings for the user that got the duplicate.

I have "invites as tentative" set to OFF in my settings (and by default for my domain's settings) and haven't been getting duplicates.

Exactly Bert Garrett-Tuck! I'm glad you can replicate the issue.

I've been theorizing that what happens here is one of your many EAS devices or maybe SM itself is putting the event on the calendar (as tentative). Then Outlook is trying to do the same (so there is a duplicate).

But again, with the "Add invites as tentative appointments"  OFF, things don't work well in terms of accepting appointments on some Android devices. So we have that setting ON... (and I think that's the SM default) and then boom we get duplicate appointments.

This has been going on a very long time. It seems to be low on the list and we wish it was getting more attention. We've been told in various support tickets that some point after MAPI goes live development may come to this. We anxiously await.

I’m also noticing duplicate appointments in my calendar. I use EAS and SharePoint with Outlook.

The duplication of appointments seems to occur after I perform a minor upgrade of SM.

Not all appointments are duplicated and it’s happened on several occasions now.