Contacts and calendar on Android phones


I am considering starting to use Runbox but I have a question about something that is not clear to me.
I need to (also) use it on my Android phone.
It is essential for me that Runbox will provide both calendar and contacts that can be set as default calendar and contacts on my phone.
Doing a lot of searches on the matter, it seems to me that Runbox has been very slow at adapting things like webdav, cardav etc., taking years to implement them.

To this moment it’s not clear to me if Runbox now has this covered properly, and if it will fully support calender and contacts functions on Android phones. (as other email services such as Proton and Tutanote do)

Any insights?

Runbox supports both CalDAV and CardDAV. On Android you can use the app “DAVx5” to sync your calendar and contacts to your phone:

Runbox doesn’t currently support WebDAV to sync your Runbox files.

1 Like

My 0,05€ on this.

Runbox indeeds supports CalDAV and CardDAV.

However, it lacks support for something as basic as sending e-mail invitations: worse than that, it actually worked and now it is not working.

(This was posted in

So, basically, one can receive calendar invitations, but it cannot send since a few weeks ago. As for the web interface, it was never possible to send invitations that way (only via apps like Google Calendar or Thunderbird).

I’ll raise this with the team. The invitations never worked as well as I would like but as you say they were at least sent out. We haven’t changed anything deliberately regarding this so I will see if I can find out what is going on.

Dave, this would mean a lot.
For you information, it was working well with Google Calendar + Davx5, as well a Mozilla Thunderbird.
It worked flawless to me.
You have the logs and you know how it was being sent (which server was sending them, etc).
I work in IT too, and I know that what we are asking breaks the whole change process. Moreover, it may open more people upset because THEIR configuration does not work.
But between not working at all and working halfway through… as long as making the old config work doesn’t break any working feature (regression testing!), I believe it would be an important effort.
I am available for any testing you may find necessary!


Hi again, Dave.

Any news on this topic?

When do you expect to have it working again?

Carlos Dourado

Hi again.

It’s been two months and we have got no feedback from this (very important) topic.

Please, update us on this.

I feel I have gone years back in time.

Once again, even if the invitations sent via app do not working, handling them via the CALDAV is a must.

I do not know any caldav client for Android which is able to handle the invitations, but please let me know if there is.

Right now I am stuck sending invitations only via Thunderbid Calendar on my PC, which makes no sense in 2024.