Microsoft Teams Calendar calendar invitations sent in emails to MS Exchange accounts

Microsoft Teams Calendar invitations sent in emails to MS Exchange accounts are _not_ a normal .ICS file, but instead, a base64-encoded blob.

When receiving such invite, sent to a Microsoft Exchange account, on macOS Mail (macOS- 13/Ventura), the email shows a calendar-like invitation banner at the top of the email, and, contains what appears to be an .ICS file (a calendar item file) —

BUT

• the .ICS file is *empty*

- zero bytes

• if the 'accept' button is pushed ( ! @#?! ), then:

- the email closes;

- the email disappears — it cannot be found within the Mail app;

- the calendar item does *not* go on to invitee's calendar;

- the accept action does not go back to the inviter.

SO

- Do _NOT_ hit a button on the calendar banner.

- Don't bother to download the .ICS file, nor to open or preview it.

Use one of these two workaround methods to deal with a macOS email containing a Teams Meeting invitation, sent from Microsoft Teams.

METHOD [ 1 ]

- save the email to the desktop as an .EML file

- (drag the email to the desktop, or, )

- (File » Save-As » Raw Message Source)

- open that .EML file ... double-click it.

- .EML file opens in macOS Mail

- NOW the .ICS file attachment has content.

- Open (or save & open) the .ICS file attachment.

- Normal calendar invite operations continue as normal.

METHOD [ 2 ]

- save the email to the desktop as an .EML file

- open that .EML file in a plain text editor.

- copy the base64-Encoded blob from [Content-Type: text/calendar] to a new file, 'b64.txt'.

- on terminal command line, from the working directory of file 'b64.txt', execute:

cat b64.txt | base64 -d > b64.txt.ics

- open that output file -- from command line, if desired:

open b64.txt.ics

- Normal calendar invite operations continue as normal.