Use Thunderbird calendar reply address when creating invitations, not the nextcloud email user email address

[Findebug]

Is your feature request related to a problem? Please describe.
I have a "work" calendar and a "home" calendar on the same nextcloud user accounts.
In Thunderbird the user can select work email as the reply address for work calendar invites and their home email address as the reply address for calendar invites from the "home" calendar. However when an ivitation is created on Thunderbird, nextcloud overwrites the reply addreses with the nextcloud user email address.

Describe the solution you'd like
If a user creates a meeting invite on their "work" calendar, Nextcloud should set the reply address to the work calendar email address specified in Thunderbird
If a user creates a meeting invite on their "home" calendar, Nextcloud should set the reply address for the invite as the home calendar email address specified in Thunderbird

Describe alternatives you've considered
I guess an work around would be to set up two accounts for each user, one for work, one for home, but I would prefer to only have one account to manage per user.

[mlegner]

I'm experiencing the same issue and would be interested in @Findebug's proposed solution.

[biva]

Isn't it a duplicate of #5080 ?

[Findebug]

Looks similar, probably related. However slight difference is I'm creating the invite from Thunderbird, not Nextcloud. Nextcloud then overwrites the email reply address that is set in the Thunderbird calendar with the nextcloud email address. I would like it to keep the Thunderbird email address

[tcitworld]

From what I can read in https://datatracker.ietf.org/doc/html/rfc6638 it would require the alternative email to be registered in Nextcloud for the invites to be sent. We need to expose it in calendar-user-address-set.

• Have a way to provide more alternative emails in Nextcloud (probably the part the more open for discussion)
• Get and return the list of alternate emails for an user here https://github.com/nextcloud/server/blob/master/apps/dav/lib/Connector/Sabre/Principal.php#L499-L518
• Implement getAlternateUriSet in https://github.com/nextcloud/server/blob/master/apps/dav/lib/CalDAV/Principal/Collection.php

[szaimen]

• Have a way to provide more alternative emails in Nextcloud

Gets currently addressed in #26866, afaics.

[tcitworld]

Basically it's easier if you select « Choose client side-scheduling » in the Thunderbird calendar's properties, then TB does the sending for you and Nextcloud isn't involved.

[tcitworld]

@szaimen Thanks for the link, that's a nice surprise.

[distefam]

It seems that this issue is affecting invites created from iOS and macOS calendars as well.

[tcitworld]

If you have the opportunity, please give #31029 a try (should apply to NC 23+ without too much conflicts). When using Thunderbird, make sure the organizer is correctly set to your secondary email in the attendees panel (it seems it doesn't always follow what's set in the calendar properties).