mu4e fails to recognize any calendar invitations

[averter]

Expected or desired behavior

mu4e correctly displaying calendar invitations and showing the corresponding buttons (accept, decline, etc). This used to work until I have recently changed email accounts + moved to version 1.8.x.

Actual behavior

Similarly to issue #1660 Calendar Invitations in vcal format are shown as regular attachments. This happens always.

Steps to reproduce

This is the relevant part of my mu4e configuration

;; Use gnus article view
(setq mu4e-view-use-gnus t)
(require 'mu4e-icalendar)
(mu4e-icalendar-setup)

(require 'org-agenda)
(setq gnus-icalendar-org-capture-file "~/org/NOTES.org")
(setq gnus-icalendar-org-capture-headline '("Calendar"))
(gnus-icalendar-org-setup)

Versions of mu, mu4e/emacs, operating system etc.

I am using mu4e 1.8.6 and emacs 27.1.

Any other detail

I am using the gnus-based message view and have tried all the solutions suggested in #1660 .

[djcb]

@Chris00, any idea?

(Note, mu4e-view-use-gnus is long gone, no need to set it.)

[Chris00]

An example of message exhibiting the problem (an attached file, bit a copy/paste) would be good.

[averter]

An example of message exhibiting the problem (an attached file, bit a copy/paste) would be good.

Thanks for the quick reply. I've created a gist of an edited email available here

The message might look a bit weird/distorted, since it has been sent to my work email and then I've used a thunderbird filter to automatically move it to my protonmail account.

[Chris00]

Your attachment is declared with the type

Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=calendar.ics
Content-Type: text/calendar; name=calendar.ics
X-Pm-Content-Encryption: on-import

It is not a request to know whether you are attending or not, contrarily to the following calendar invitation

Content-Type: text/calendar; charset="utf-8"; method=REQUEST
Content-Transfer-Encoding: base64

Importing such a file into Emacs calendar would be nice but this is an additional effort w.r.t. the current implementation (which heavily uses what Gnus provides). I do not have time for that right now — maybe after the 16th of August.

[averter]

I am already able to import the ical file using ical2org, and I am happy to share my setup if anyone is interested :-).
Regarding the strange format, when opening these emails using Thunderbird I am prompted to press the accept/decline buttons, and I am clearly in the attendees list. What is it then that changes the method of invitation from REQUEST to the other "spurious" one? I have tried creating invitations, both using Teams and Thunderbird, and inside mu4e the buttons never show up, although as mentioned everything seems normal when using Thunderbird. This used to work before so I am really confused O_O.

[Chris00]

You are right, I just added ; method=REQUEST and the buttons do not show up. I'll try to investigate that (but I likely will have no time before August 16, sorry); it may well require to (re)investigate how Gnus triggers the buttons (it probably doesn't either in your situation).

[averter]

That is absolutely fine and thank you very much. I have been learning elisp lately, so I will also do some separate/minor investigations of my own on how Gnus handles the buttons. Cheers.

[kthu]

Possibly not the same issue, but I too have experienced problems with ical invitations (mostly from ms teams) misbehaving after recently upgrading to mu 1.8. The problem I am seeing is that the To: field in the generated reply emails are no longer pre-populated, requiring me to manually fill it in every time.

The other functionality seems to work as before - The action buttons still show up in the invitations, a reply mail is still composed, and events are still added to my org calendar.

This is using Spacemacs/Emacs 28.1, mu 1.8.6, and the same mu/gnus config lines listed in this issue.

[averter]

Possibly related issue on nextcloud...

[averter]

I've found what was causing this issue. Essentially, the emails with ics attachments had been moved from the email account where they had been sent to another account (using thunderbird filters and separately to mu/emacs). For some reason this changes the emails and destroys the structure that is needed to generate the buttons via gnus; if I remove the filter all works well. In any case, it is not a problem with mu/gnus and I am closing this.
@kthu feel free to open a separate issue with your problem.