Support alternate mailaddresses from a users configured e-mail addresses

[Keeper-of-the-Keys]

Short description
I would like to be able to set the e-mail that is used to send an invitation for an event on my calendar.
Since there are multiple aspects and this has things that need to be implemented server side as well as in the calendar app I'm opening the issue here.

Describe the solution you'd like
In an ideal world I would see 2 things happen:

1. In the calendar app or in personal settings allow the configuration of the outgoing e-mail/alias that is to be used automatically.
2. In the calendar app allow the user to chose the from address when creating the appointment.

The reason that (1) is needed is that when using caldav clients they will not have a way to be aware of the e-mail accounts/aliases available to the user on the server.

When (1) is available (2) is a poweruser feature.

As an alternative to (1) what may also be possible is to scan if any of the configured mail addresses has a corresponding MailProvider.

Describe alternatives you've considered
I have tried adding a second e-mail in my personal settings but while it matches the e-mail address that is available it was not used.

Additional context
Specifically for my setup the e-mail address of my user is set by SAML and is internal whereas I have an alias that I prefer to use as well as liking to use unique addresses when I send messages to companies etc, also I can't change said e-mail address.

I have been looking at the code and am now sanity checking myself based on my understanding and hoping for some feedback/brainstorming before I start hacking away.

current flow

1. Appointment with an external party is created in calDAV client (calendar app, thunderbird, gnome calendar, phone app etc.)
2. calDAV backend determines if the user has a mailprovider that matches the e-mail address configured in their user settings
3. If (2) send using that mailprovider
4. If not (2) send with system mail settings if they exist (eg. noreply@domain)

[Keeper-of-the-Keys]

I hope this was not too rambling, I'm starting to look at the source but would like input from others, also I wrote this over several days and in the middle added system-wide SMTP settings to nextcloud to test.

[Keeper-of-the-Keys]

Based on some further testing either my assumption as to why things work the way they do was wrong or I did something wrong because when I created an appointment from my phone calendar it never sent an e-mail.

[SebastianKrupinski]

Hi @Keeper-of-the-Keys

This will require custom dav property in the CalDAV, then there is also the question of which email addresses do we use? At the moment there are several options, from the users profile, then the users configured email accounts and the users email account aliases.

[Keeper-of-the-Keys]

This will require custom dav property in the CalDAV, then there is also the question of which email addresses do we use? At the moment there are several options, from the users profile, then the users configured email accounts and the users email account aliases.

From my observation on my system for my account invites get sent from the noreply address even though I configured a second e-mail address that exists as a MailProvider, for my wife the "main" address matches the MailProvider and gets used.

When creating an appointment on my wifes phone it sends an invitation whereas on my phone it does not but I suspect that that is an issue with the SailfishOS calendar not setting an organizer.

I think to begin there could be a loop that goes over configured addresses and sees if they have a MailProvider and uses the first match, this would require the least changes and improve how things work for people like me but I can totally see that people would want to control which MailProvider is used via a setting.