Calendar invites not sent when using 3rd party CalDav client

[chaptergy]

Steps to reproduce

1. Connect to the CalDav Server via DAVx5
2. Create an event with attendees in a synced calendar

Expected behaviour

The attendees are each sent an invite via email

Actual behaviour

The calendar was updated online but no invites were sent. However when changing it in the official calendar web app, invites are sent out, so the issue can't be my email setup.

Server configuration

Operating system: I unfortunately don't know

Web server: Not showing in the server info settings tab either

Database: mysql

PHP version: 7.3.11

Nextcloud version: 17.0.0

Updated from an older Nextcloud/ownCloud or fresh install: Update

Where did you install Nextcloud from: My hosting provider did it

Signing status:

Signing status

No errors have been found.

List of activated apps:

App list

Enabled:
  - accessibility: 1.3.0
  - apporder: 0.8.0
  - calendar: 1.7.1
  - carnet: 0.18.7
  - circles: 0.17.8
  - cloud_federation_api: 1.0.0
  - contacts: 3.1.6
  - dav: 1.13.0
  - deck: 0.7.0
  - federatedfilesharing: 1.7.0
  - federation: 1.7.0
  - files: 1.12.0
  - files_pdfviewer: 1.6.0
  - files_rightclick: 0.15.1
  - files_sharing: 1.9.0
  - files_trashbin: 1.7.0
  - files_versions: 1.10.0
  - files_videoplayer: 1.6.0
  - impersonate: 1.4.0
  - logreader: 2.2.0
  - lookup_server_connector: 1.5.0
  - metadata: 0.10.0
  - nextcloud_announcements: 1.6.0
  - notifications: 2.5.0
  - oauth2: 1.5.0
  - occweb: 0.0.4
  - password_policy: 1.7.0
  - polls: 0.10.4
  - provisioning_api: 1.7.0
  - serverinfo: 1.7.0
  - sharebymail: 1.7.0
  - spreed: 7.0.1
  - tasks: 0.11.3
  - text: 1.1.0
  - theming: 1.8.0
  - twofactor_backupcodes: 1.6.0
  - twofactor_totp: 4.0.0
  - updatenotification: 1.7.0
  - viewer: 1.1.0
  - workflowengine: 1.7.0

Nextcloud configuration:

Config report

{
    "system": {
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "***REMOVED SENSITIVE VALUE***",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "17.0.0.9",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": "6379",
            "timeout": "1.5",
            "dbindex": "0"
        },
        "filelocking.enabled": true,
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "log_type": "syslog",
        "syslog_tag": "nextcloud-nx3851",
        "simpleSignUpLink.shown": false,
        "upgrade.disable-web": true,
        "updatechecker": true,
        "mail_sendmailmode": "smtp",
        "maintenance": false,
        "has_rebuilt_cache": true,
        "loglevel": 2,
        "app_install_overwrite": [
            "occweb"
        ],
        "skeletondirectory": "\/var\/www\/html\/themes\/hetzner\/skeleton"
    }
}

Are you using external storage, if yes which one: nope

Are you using encryption: no

Are you using an external user-backend, if yes which one: no

Client configuration

App: Davx5 2.6-ose

Operating system: Android 9

Logs

Unfortunately I don't have access to any of the logs

[alxnbl]

I encoutered the same issue.
I gave some additional information on the help form, I hope it can helps : https://help.nextcloud.com/t/nextcloud-calendar-not-sending-invitation-when-creating-from-android-app/69363/3 .

[CyrilBrulebois]

Having performed a few tests, it seems to me I can confirm there some restrictions as to when invites (for attendees) are sent:

1. if you're writing to a calendar that's shared by someone else, invitations aren't sent;
2. if you're writing to your own calendar, but the organizer property doesn't match the mail address defined in Nextcloud, invitations aren't sent either.

This can be verified by downloading the ICS file for a given event, the relevant field is ORGANIZER. It can look like this, e.g. with various Android sync clients:

ORGANIZER:mailto:cyril@example.org

or like this, e.g. from iOS:

ORGANIZER;CN="Cyril Brulebois";EMAIL="cyril@example.org":mailto:cyril@example.org

It seems the mail address after mailto: is the part that matters, and what must match what's defined in Nextcloud. This means that the first use case I've mentioned is actually just a particular case of the second one, but one might get confused when testing (e.g. Android client for a person who gets access to a shared calendar → KO vs. iOS client for a person who shared their calendar → OK but that's actually not at all an Android vs. iOS difference in the end!).

As it stands: One needs to make extra sure that the configured sync client knows about the proper mail address, and that one writes to a calendar which is linked to the same address.

It might be possible to have some kind of policy to allow (or not) other persons having access to an agenda to have invitations sent out, I've seen the notion of privilege, ACL, etc. so maybe the building bricks are already available (see schedule-send*), but I won't dive deeper into the code today.

Hope this help!

[tcitworld]

if you're writing to a calendar that's shared by someone else, invitations aren't sent;

This is #26668 (previously at nextcloud/calendar#2055 and related issues, especially #15676 )

if you're writing to your own calendar, but the organizer property doesn't match the mail address defined in Nextcloud, invitations aren't sent either.

This is #27201

[distefam]

@CyrilBrulebois Did you manage to get the organizer property to be the correct value on iOS or macOS?

[lkthomas]

if you're writing to your own calendar, but the organizer property doesn't match the mail address defined in Nextcloud, invitations aren't sent either. <- this statement help me solve the Android DAVx5 setting, the "account name" on DAVx5 can't set randomly and has to match the email which you set on your NC account, I guess you can rename your account to match it on DAVx5 if you got it wrong.

[rurod]

@distefam Hi, I was looking for a solution to achieve this on iOS too.
If you use the email rather than the username to log into the nextcloud account, it works.
I have tried this on :

• iOS 17.0.3
• MacOS Sonoma 14.1.1
• Nextcloud 27.1.3
• CalendarApp 4.5.3