How can I link a calendar with a Mail Address?

I have 2 calendars and 2 mail addresses configured.
em Client sends the invitiation from the second calendar with the wrong mail address.
How can I “link” the calendar to a specific mail address?

Are the calendars synced with a provider? If so, are you creating the event in the correct calendar?

Otherwise, invitations for events in a local calendar will be sent from the default email address.

calendar is synced, yes but not with the provider I got my mails from.

If so, are you creating the event in the correct calendar?

Yes

When the calendar is online, eM Client does not send the invitation. Rather is is sent by the calendar server. Check what email address is setup for that calendar using the web interface for the provider.

This can’t be the case:
I am using the provider posteo and they can’t even send server side invitations. They are clearly send be em client.
But this is not my posteo account concerning my problem.

The only link between the mail and caldav provider is em client.
This features is even advertised here:
https://www.emclient.com/features-calendar

One way to check if eM Client is sending the invite is to see if it is is the Sent folder.

But that is very unusual that a CalDAV does not send invitations. So, in that case the invite is being sent from the default email account in eM Client. 

Good morning,
also have my calendar at posteo (caldav). I can only send invitations via eMClient, not via the website posteo/Calendar posteo. A sent invitation is located in the sent folder. I could not find an option to change the email address of the invitation.
Even when changing the default mail account, the sender mail address was no different.

In my case its even weirder, my provider could send mails (and it does as long as I use my mobile phone for new events) but nevertheless em client is sending the invitation out (yes its in the send folder) and I have no option to change the mail address.

I thought you said the provider can’t send server-side invites?

No it can. Posteo can’t (this is my other provider)
Posteo was just an example

Yes, please be specific.

When you say you’re “using the provider posteo and they can’t even send server side invitations” but then you say your “provider could send mails” that is just confusing for everyone.

Is your phone using CalDAV to connect to this posteo provider?

You can only send invitations via the eMClient, not via the website posteo/Calendar posteo.

OK, thanks Huber.

Usefulvid, please go to Menu > Tools > Accounts and change the default email account to the one you want the invitations to be sent from. That means you need to highlight the account, then click on the star icon. Restart eM Client just for good measure.

Now create a new event in this posteo calendar, and invite an attendee. Once that is sent, go to your Sent folder for the account you just made default and see if the invitation is there. 

I had already tried this. The invitation is not sent via the standard mail account. The sender mail address does not change.

Now create a new event in this posteo calendar,

As I said, posteo is not part of this problem it was just meant as example. Nevertheless thanks for the hint I will take a look in the options.
Is there any way to trigger server side invitations if the calendar supports it?
The calender in question can send server side invitations but em client takes over before server side invitation is sent out.

But this is not my posteo account concerning my problem.

When the calendar is online, eM Client does not send the invitation. Rather is is sent by the calendar server.

I only mentioned posteo because you suggested that an online calendar is sending mails without em Client. And posteo is using caldav and CAN not send inivitations server side.
It was just meant to proof you wrong.

Again: my problem is that a calendar from the provider Hetzner (which could send server side invitations) is sending invitations from a mail account which is only in em client.
And I can see the mails in the sent folder.
I have 2 Mail addresses configured in em client and want to have the choice how the inivtation is sent.
Server side would also be fine for me but at the moment the hetzner calendar sends inivitations via a mail account in em client (but hetzner calendar could send server side, it works as soon as I use it from the smartphone)

Yes, you used an unfortunate example, and Huber clarified that posteo cannot send server-side invitations. Not all CalDAV servers can do that, but generally they can. The point is that if the calendar is synced with a fully implemented and configured CalDAV, the server will send the invitation.

As you have had issues with that provider in the past, maybe just consider that they are not correctly configured, and a poor example to quote in future.

Can your phone or other email client send invitations using this Hetzner provider using server-side?

Can your phone or other email client send invitations using this Hetzner provider using server-side?

yes I can perfectly send it from my mobile phone

Is the phone using CalDAV?

Yes (davx5 is the sync app)
I own the domain, I can offer to create you a mail account if you want to test it yourself