Inviting a circle does not resolve its members

[st3iny]

Steps to reproduce

1. Create a circle with some users (which have email addresses).
2. Create an event and invite said circle.
3. Save the event.
4. Export it

Observe, that the ICS contains a single, strange attendee, e.g.:

ATTENDEE;CN=invite-test;CUTYPE=GROUP;PARTSTAT=NEEDS-ACTION;ROLE=REQ-PARTICI
 PANT;RSVP=TRUE;SCHEDULE-STATUS=5.0:mailto:circle+RQzSHWoHKpZAT67fCOWstupXE
 cStZfN@

Is this intended behavior, i.e. is the circle not supposed to be resolved?

EDIT: Nope, that looks like a bug (see below).

Ref #5420

Expected behavior

A circle's member should be resolved and added to the event directly. At least, if members are users with email addresses. Otherwise, scheduling won't work.

Actual behavior

There is a single attendee with a cryptic, malformed email address.

Calendar app version

main, stable5.1, c.nc.c

[st3iny]

Nope, that looks like a bug. The members should be resolved. Quoting the original PR:

Members of the circle will be imported as standard attendees. Each member gets
assigned to the circle group entry by assigning them to the group uri using the
iCal member property: "MEMBER='mailto:circle+CIRCLEID@CIRCLE_INSTANCE'".

Circles added to the list of attendees get imported only once and are not
synced yet. While adding a circle, a notice about this is shown to the user.
Only members of local circles which are local users get imported.

[ChristophWurst]

I can't reproduce the bug. I've invited a circle with two members that have an email address. I do see one CUTYPE=GROUP and two CUTYPE=INDIVIDUAL as the three ATTENDEEs.

ATTENDEE;CN=invite-test;CUTYPE=GROUP;PARTSTAT=NEEDS-ACTION;ROLE=REQ-PARTICI
PANT;RSVP=TRUE;SCHEDULE-STATUS=5.0:mailto:circle+RQzSHWoHKpZAT67fCOWstupXE
cStZfN@

Did you redact the hostname or was @ really the end of the attendee value? I have something like

ATTENDEE;CN=Zirkel;CUTYPE=GROUP;PARTSTAT=NEEDS-ACTION;ROLE=REQ-PARTICIPANT;
 RSVP=TRUE;SCHEDULE-STATUS=5.0:mailto:circle+9iEDy8qZEQ86sUJzpa4UtRZivLPU2x
 i@localhost

[baby-gnu]

Seems related, my nextcloud email address has a lot of bounces

Reporting-MTA: dns; mx.example.net
X-Postfix-Queue-ID: B74D51FD3
X-Postfix-Sender: rfc822; cloud@example.net
Arrival-Date: Sun,  6 Apr 2025 15:19:07 +0200 (CEST)

Final-Recipient: rfc822; circle+XXXXXXXXXXXXXX@cloud.example.net
Original-Recipient: rfc822;circle+XXXXXXXXXXXXXX@cloud.example.net
Action: failed
Status: 4.4.1
Diagnostic-Code: X-Postfix; connect to cloud.example.net[X.X.X.X]:25:
    Connection refused

It looks like when inviting a circle, an email is sent to circle+… which does not exists.

I don't see any requirement for a dedicated circle@<NEXTCLOUD FQDN> email box, any idea?