How Microsoft Planner Works

Published Mar 06 2020 02:22 PM 15.9K Views
Frequent Contributor

Planner is pretty straightforward to use, so I guess you all know how it works – but the aim of this blog is to explain how some of the features are implemented and the parts of the Microsoft stack they use – which I hope will help you understand some of the scenarios where Planner might not work.  This could be situations where you are in certain configurations where you might have changed some settings in Exchange Online or Office 365 not realizing that this would impact Planner.  Read on to find out how Planner really works!


I’ll be illustrating this blog with my favourite plan – my Office 365 Change Management plan – that gets auto-populated from the Office 365 Message Center. 


The features I’ll be concentrating on are Comments, Attachments and notifications/alerts.




When you add a comment to a task, where does it go? 

Adding a comment.jPG

It actually gets saved to the Group inbox for the Group that the plan belongs to – as a thread.  When you load a task it is reading the thread and putting the entries into the comments section with timestamps.  If I visit my Group inbox for my Office 365 Change Management Group I will see it.  In my case the name is the same – this needn’t be the case – but you can get to the right place by selecting the ellipses when in the full plan view and selecting Conversations.

Comment viewed from OWA.JPG

The e-mail thread also contains a deep link back to the task in question.  Once you understand where the comments are stored, and this isn’t just an e-mail of the comment, this is the real thing and the only place it is stored, then this helps explain some scenarios you might see.


My comments are not getting saved?

A user might add a comment – and they see it in the task, but then it disappears or is gone when they re-load the tasks.  This happens when the user in question does not have permissions to send e-mail to the group – or something else in the flow of the message to the Group inbox is blocked in some way. You might also get a message at the foot of the page in Planner telling you something failed – the details (Correlation ID and timestamp) are very helpful for us in finding what the problem was. 

It can be that the user is a guest and the Group is configured not to let people outside the organization email the group. 

Another thing you may see in your own inbox is a non-delivery report (NDR).  This document gives some help with understanding what might give an NDR, and how to unblock it.  Any domain restrictions could impact delivery too – these e-mails will look to come from the person who added the comment, but you may need to review how the user is configured and what their ‘mail’ property really is.  It might look like spoofing if is being sent from one domain but looks like another (this can happen with Hybrid scenarios). 

We have also seen issues with 3rd party disclaimer add-ins – where there may be a disclaimer added to each e-mail.  The route this takes for Planner to Group e-mails may get blocked by Exchange.  One option is to configure an exclusion so that this type of e-mail does not get the disclaimer. 

I’ll be coming back to hybrid a couple of times in this posting – but hybrid Exchange is a scenario that to avoid issues – see for more details. One of the key things is that users with mailboxes on premises need to be known as MailUsers in the online environment – not just Users.

One scenario I’d describe as a ‘gotcha’ is if you copy and paste an e-mail into a comment and then save – it gets truncated.  The reason here is that the format of From: and To: fields in the e-mail get special treatment in Exchange as it thinks this is a reply or forward chain.  If you do need to do this then removing the From: and To” before clicking Send will work – or you could save the mail as an msg and attach instead!


Guest Users and Comments

Currently I’m not seeing comments working for guest users (3/6/2020) although our documentation says that it should – so I have raised this with engineering.


Yammer Connected Groups

One other configuration that can confuse with the comments handling is when you have a Yammer connected Office 365 Group  The design decision here was that if your Group is connected to Yammer, and you have a Plan associated with the Group – then the discussion for the plan will likely happen in Yammer.  Planner does not support using Yammer for comments – but they took the decision to not support comments at all in this scenario – just to avoid confusion with the conversations happening within Outlook.


My comments are gone!

As the comments are just the threads in the Group inbox – if they get deleted, then the comments cannot be displayed in Planner – they are gone!


If I then try and add another comment then nothing appears to happen.  If I check with F12 Developer tools or Fiddler I will see a HTTP 503 ‘The service is unavailable’ – as the thread cannot be found.

If you want to recover the deleted item, then you are probably wondering where the deleted items folder is for the Group?  You can get to it by adding the Group folders – as the Group inbox is listed when you use the right click option (from “Folders” to Add shared folder.  In the following screenshot I’d already added the folder and you can see the deleted Items folder for M365Repo lower down. Make sure to move the mail to the right inbox to get them back as Planner task comments – move to the Group inbox and not your own!



I don’t see comments in my inbox?

Comments, as you can see from the above sections, are stored in the Group inbox.  But they can also be seen in your own inbox too depending on how you have the Group configured.  The Group administrators can check an option within the Group settings (accessed via OWA, the Group inbox and the ellipses for Settings and then Edit Group – and the option is Send all group conversations and events to members’ inboxes.  They can stop following this group later if they want to.  The admin opts everyone in – then individuals can opt out.  But how this is set and if people have since opted out mean that the behavior can be different from Group to Group and user to user.


If you don’t want to follow, then there should be an option in the footer of all Group mails that come to you to unfollow – or in OWA just hover over the name of the Group and there will be an option there too.



I can’t see the attachments?

This problem could also be worded as I can’t add attachments – and the underlying functionality here is the files storage for the Group – which is the shared documents folder in the Group.  If a user of Planner does not have access to the shared documents folder then they will not be able to add attachments (either upload them to SharePoint or add from SharePoint) or view attachments added by others.

An example here – the left hand image is a task viewed by my administrator – the right hand one the same task but viewed by a guest user.  Shouldn't this just work?

Now you see me.JPGNow you dont.JPG

Now guest users ‘can’ see the shared documents folder – unless they can’t – such as when the SharePoint setting to not allow external access has been enabled. In this case, if the guest clicks through they are seeing:

That didn't work

External sharing is disabled for Documents/120902_deerpark_094_23973670405_o.jpg?web=1.


Checking in Office 365 Admin, Settings, Settings, SharePoint I see the reason for this:


This is just one example, and one I set up – there could be other permissions set or conditional access rules that might cause a similar experience.  But at least now you know where the attachments are you are better equipped to troubleshoot issues.

While I’m talking about attachments, we often get the question on why isn’t the ‘File’ option available in Teams – but just the SharePoint and Links options.  The reason is that with Planner a file would just get loaded to the Shared Documents folder – but once you are in Teams then the options are broader with channels etc.  so, it would have needed a much more flexible UI.  The decision was taken to just leave the SharePoint option – and you can use the Teams default file upload option to decide where to store any uploaded files.  This meant the Planner team could spend time on adding more value rather than re-inventing the wheel.


So, what about notifications and alerts?

When troubleshooting notifications and alerts a lot of the details about the Exchange and email configuration mentioned above also come in to play – particularly around hybrid scenarios and external users – but the key thing to understand is exactly what are you troubleshooting?  Not all emails are notifications and alerts – they could just be comments that you get because you follow a Group.  Just because you see these does not mean that you should see other notifications.  Maybe they are still turned off?  So where should I look?

Group owners can set a Plan so that the Group is emailed when a task is assigned or completed.  This goes to the Group – but if you follow the Group then you would also see this in your inbox.


The ‘group settings’ link on that dialog also gives users an option to control the granularity of mails they follow – rather than just having all or nothing.


These are individual Plan and Group settings – but you also have the Planner Notifications settings – available via the Gear icon in the top right of the Planner page:


The options available under notifications are unchecked by default and there is also a Learn more link to  Currently these options are not available in the Government cloud (GCC, GCC High, DoD) and this is due to one of the services that is used by Planner for notifications and alerts not being available in those secure environments.


As you can see, with so many options at the plan and group level – some of which can be tailored by the user – you cannot always assume that just because a user gets a mail that other users will get the same mail – or that getting mail for one plan means that you should get mail for all plans.


*** Update 6/26/2020 *** Group Owners v members. 

You shouldn't need to worry about this if your groups are created in Planner, Teams, OWA or OneDrive as if you create the group then your will be an owner, and more importantly also a member.  Planner and OWA for example just check that you are a member - and if you are just an owner and not a member, then no Planner for you!  Same with OWA, you will not see Groups displayed unless you are a member, even if you are the owner!  As of today the only places I found that will create a group and just add you as the owner are Azure AD Admin Center and via the Graph API.  So if you are using those tools to create groups make sure to also add your owners as members!


You should also bear in mind that with any set of inter-connected services there can be some transient conditions that may stop some features from acting as expected – so either try again – or take a look at the Service Health Dashboard (SHD). Attachments not working for example might not trigger an SHD post for Planner – but it might show up as a SharePoint issue. Likewise some Azure problems might impact Planner – so seeing an Azure issue might give you a clue as to why Planner is having issues too.

I may update this posting from time to time - if I come across any other scenarios that deserve mentioning.


Occasional Visitor

Thanks for this explanation.


It made me realize the reason for us having strange files in our group SharePoint! And I'm surprised really, that you let file attachments leak into the group SharePoint document library like that!


I would consider the current way attachments are handled to be a bug. A bit more politely stated; There's room for improvement! And I actually just found an item in the Planner Uservoice regarding this. Dating back to 2017. 


Please have a look at it and I hope you agree that this situation can be improved. (Added a comment in there with a suggested way of improving this)



New Contributor

The second notification option is available in GCC Planner


I would really love it if comments and conversations could be removed from Outlook entirely, and instead use a Teams channel.  


With Teams-created inboxes being invisible from the directory by default, many users never know about the Group inbox at all, and trying to explain how to get there and setup notifications is onerous.  It would be much much cleaner if comments could be stored in a Teams channel instead, where my users are already interacting.


@Brian Smith : is the PowerAutomate flow that you used to create the Office 365 change management plan used in your example available as a template somewhere?  That's an amazing idea!

Frequent Contributor

Hi @Gustav_ - there is no leaking and this is not a bug - that was the design choice from Planner to store the attachments in the SharePoint site.  Both the plan and the SharePoint site are 'owned' by the group - so not sure why you consider this a leak, although I agree maybe the structure of where they are stored could have been designed differently.  Nothing to stop you loading files up to SharePoint and then linking, which is the preferred workflow when using Planner in Teams.  Thanks for the feedback.


Hi @bcobra - yes, the second option shows up - but it doesn't work and should not be displayed.  This is a bug.


Hi @Arin Komins I did try PowerAutomate (Flow) but found that Azure Functions gave me the best control and was easier for me to use.  I did post a blog on using a Connector too.  The very good news is that in the not too distant future the Message Center team will be implementing something similar out of the box :) for Message Center to send to Planner.  If you can't wait then see for my solution.  Also good feedback on the Comments.  Planner was introduced before Teams was a thing - if they were choosing now the team might very well make a different choice - the current design does create some challenges with the possible ways that can change the behavior of e-mails.  No current plans to change the design - but never say never.




@Brian Smith - I'll have to wait until the Message Center team does its thing; we don't have Azure easily in use in my environment, but that is excellent news.  I very much look forward to being able to use this!


...and shame on the design choice; I know Teams wasn't a thing; but it is now.  I should wander by the Planner uservoice and see if we can get some interest on it.  Thanks for the clarification!  This post was superhelpful.

Occasional Contributor

@Brian SmithI definitely see the simplicity in having Planner store attachments in the Group's sharepoint library, but seems a little concerning that users could unknowingly delete or modify files attached to a task when they're browsing the group's files.

Occasional Contributor

It happened to us, people wanted to clean up the root folder and deleted important Planner attachments. At least, you should store it in a Planner Folder.


And because notification is working only via mail (all or nothing) Departments start moving to Monday for tasks, as they depend on commenting on tasks and get to know, when somebody replied, without everyone else get to know.

I know some can unfollow the inbox. But I don't want to unfollow, I want to the the inbox E-Mail, but no for every comment; only the once I am assigned to, I replied to, I created, I follow and I get mentioned. Best would be, I can decide separately what I want receive and what I don't want to receive via email + Mobile push for all of this.


How is everyone else working with the comments, if you can't control the settings in larger teams. I had to turn of email, because it went crazy.

Appreciate any help

Frequent Contributor

Didn't read the whole blog, because the frustration over poor design choices and self inflicted limitations got to high...


Instead of a development team creating a great product, we get a "well, that's just how groups, guest access, etc. work and we try to make our best. Here is some information about how you can work around it." Of course it's easier to dump comments in the group mailbox and telling every user that thinks he's just cleaning up a mailbox that he is actually deleting valuable information in another place, then idk choosing a better place to store comments. Where the user is expecting it?  


The whole group mailbox design is such a disaster, I advice my user to just simply ignore it's existence. It's not acting as a real mailbox, so why bother to send email to it and even in really small groups of users creating a Microsoft Team for them is much easier to use and explain.

Frequent Contributor

Thanks for the feedback @Michael Goth and @Michiel van den Broek - my aim as a support engineer was to help with the understanding of how this all fitted together.  I also work closely with the engineering team to help them understand some of the challenges our users face with the design.  On the 30th the Planner team are wanting to talk with customers - if you have the time I'd love them to hear your feedback 1st hand.  Also keep a look out for an "Ask Microsoft Anything" (AMA) session on Planner where this feedback would also be useful.

Best regards,


Senior Member

Hi @Brian Smith,

I just tripped across this thread, and I missed the AMA, but I appreciate all the detail in your blog post - that is super useful troubleshooting info.

Where is the best place to post feature requests for Planner?  The biggest one for us is rich text in the notes field (although a larger field length for checklist items would also be really handy).

Frequent Contributor

Thanks @Glen_Martin - the best place for feature requests is UserVoice - and alwasy best to vote for existing ones if they match your requirements - such as this one for rich text - and there is also a generic 'improve checklists" item  I'm sure there will be another AMA session so that is also a great place to get attention to ideas.  

Best regards,


Regular Visitor


J'utilise depuis peu Planner pour mon entreprise de 20 employés.

Je trouve cette application dynamique et très bien conçue pour le suivi des tâches.


Il y a cependant 2 aspects que n'arrive pas à comprendre par rapport à la configuration ou la politique de Microsoft


- Pourquoi pouvons-nous pas mettre une récurrence à une tâches?

- Pourquoi l'employé ne reçoit pas le commentaire de la tâche tant qu'il n'a pas "accepté" cette dernière. Comment procéder pour être sûr que le message est bien parvenu au destinataire? Doit-il se fier uniquement à la boîte de réception du groupe, et non à sa boite de réception des ses e-mails?






Occasional Visitor

@Brian Smith  thank you for this, very helpful. Do you know when we'll be able to configure our own upload libraries?? It's a feature we used to have, and it would be helpful with document storage set up the way they have in SPO. Thank You.

Frequent Contributor

What do you mean by "it was a feature we used to have" @swearNotakaren ?  I didn't think Planner ever offered a choice of library locations, and also not aware of any plans to add it.  You can of course add an attachment as a link from anywhere, but I can understand that isn't quite what you are looking for.

Best regards,


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