Outlook won't let me open attached files, saying I need a Microsoft 365 subscription, but I already have one.

Have the same issue with my "non-outlook" subscription address, but for only selected use cases:

1. (bad) only fails if I double-click to open.
2. (good) If I click the dropdown menu for the attachment and select "Open in Excel" then New Outlook recognizes the MS account and Excel desktop opens.
3. (good) If I click the attachment to show the preview, then select "open in excel" at the top of the window, New Outlook recognizes the MS account and Excel desktop opens.
4. (good) I added the MS account in New Outlook Settings -> Your Accounts > Additional Microsoft Accounts, and New Outlook recognizes the MS account there, shows the expiration date, etc. (for emphasis: I told New Outlook about the account, and it seems to have accepted it).

In three out of four scenarios here (the only ones I could think of trying), New Outlook recognizes the account just fine. From a user experience perspective, that's inconsistent at best... if you want to force outlook accounts then do it everywhere, make it overt, and and just do it.

I am 30+ years in IT, so I get that there are different teams, different codes bases, etc. at play here and things are not always consistent once everything is stitched together. But to the average end user it sure seems like a bug. Most will not think "hey, I can add an email alias to solve this", but rather be frustrated that one of the apps in their paid service does not consistently recognize their right to use another app in the same paid service. The optics are not great on this one.

p.s. finding some humor here (or insult to injury?): a couple days ago I clicked the "go premium" button to see if I could connect my existing subscription on the next screen (I could not). And then Microsoft sent me a reminder email

to "complete the purchase" of premium that ended up in a shopping cart. (and yes I cleared the cart :) ).

I'd be happy to help, if your account is registered with a third-party email address, New Outlook will not recognize it as a Microsoft account, so it will not recognize the license correctly, it is recommended that you add an @outlook.com alias to your account, and then add the alias to New Outlook, and set it as the primary account.

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If you don't want to add an alias, and your Microsoft 365 is a personal or family edition, then you can use the Classic Outlook application, which should already be installed with the Office suite, and you can search for "Outlook" in the Windows search box to see if it is already installed.

Hi

I'm having the same problem, been subscribed to MS365 for about 3 years and this has started occurring in the last couple of months and is really irritating.

It sounds like users are being forced to use Outlook email; why do we have to do that, in order to use a product we are paying for in full? Through work and other activities, I already have nine email addresses, I really don't want another one.

The alternative is to downgrade to an older version. Again, we are paying for the full MS365 product, why can't we use it?

This sounds off and really not happy about it. I don't see why Outlook can't recognise the license because I am using a non-MS email address. It did up until a few months ago.

Dear Y. Gilat,

Welcome to Microsoft Community.

I understand that you are prompted for a Microsoft 365 subscription when you open an Excel attachment.

I'd be happy to help, if your account is registered with a third-party email address, New Outlook will not recognize it as a Microsoft account, so it will not recognize the license correctly, it is recommended that you add an @outlook.com alias to your account, and then add the alias to New Outlook, and set it as the primary account.

Please go to https://go.microsoft.com/fwlink/p/?linkid=864833 to add an alias.

You can read the link below for more information.

Add or remove an email alias in Outlook.com - Microsoft Support

If you don't want to add an alias, and your Microsoft 365 is a personal or family edition, then you can use the Classic Outlook application, which should already be installed with the Office suite, and you can search for "Outlook" in the Windows search box to see if it is already installed.

It looks like this. It offers more complete features as well as stability.

In this special season, I wish you all the best—may your holiday be merry and bright! Merry Christmas!

Best Regards,

Jason.YA - MSFT | Microsoft Community Support Specialist