*cloud - FileLink for Nextcloud and ownCloud

A MailExtension for Thunderbird (68+) that uploads large attachments to your Cloud and generates a link you can send by mail instead of the file.

Information for


User guide


*cloud is available via Thunderbird's Add-on repository.

  1. Install it directly from the Add-ons management within Thunderbird.
  2. Go to Settings -> Attachments -> Sending to configure your Nextcloud or ownCloud account.

Password vs. App Token

Instead of storing your password it's more secure to use an "App Token " with *cloud. There are two ways to get such a token:

Handling of existing files

*cloud uses the same method as the Nextcloud/ownCloud desktop clients to decide if the local and remote files are identical.

Known issues

URL works in browser but not in *cloud

In some situations the url you use to access your Nextcloud/ownCloud account in the browser doesn't work in *cloud. This happens if your access url is redirected to the actual cloud location (plus some technicality).

Here is how you can point *cloud to actual cloud location:

  1. Open your cloud in the browser.
  2. Log in. This should take you to the "Files" section within your cloud. If it doesn't, click on the folder icon to go to that section.
  3. Copy the complete url from the url bar of your browser
  4. Paste it into the server url field in *cloud's configuration (in Thunderbird).

When you save the settings, *cloud will remove everything, that's not necessary.

If this still doesn't work for you, read on:

Here is an example of what should happen:

If things look very different for you and login still doesn't work, I'd appreciate a problem report by email containing the url you pasted. Don't be afraid, the url does not contain any secret data. Thanks.

Only one download password for all uploads

In Thunderbird's concept of FileLink Add-Ons the preferences panel is the only means of user interaction. So there is currently no supported way to ask the user for an individual download password or show a generated one. It might be feasible by unofficial methods. But that solution might break, whenever Thunderbirds API changes -- and as of early 2020 it changes frequently.

Workaround: Change the download password in the preferences pane or use multiple accounts with different passwords.

Attaching files from network shares

If you attach a file from a network share, it's uploaded to the cloud and the share link is inserted into your mail, but the file is also attached to the message. This is not a bug in *cloud but a known bug in Thunderbird. There is nothing I can do about it in *cloud, sorry.

Workaround: Copy the file from the network share to your local disk before attaching it.

Service name in messages is always "*cloud"

When the download url is inserted into the email message, the hosting service is always shown as "*cloud". It would be less confusing, if instead the actual name of the service would be shown. But this is (currently) not possible, as the text surrounding the url is part of Thunderbird. And Thunderbird insists on using the name of the extension here. there's nothing the extension can do about this, sorry.

Upload problems

Cloud admin guide

Server settings

Some settings in Nextcloud/ownCloud are relevant for this Add-On:


In some configurations a start url like https://cloud.example.com is redirected to the actual url of the cloud eg https://example.com/cloud. *cloud has to access many different paths below this url, eg. status.php. If these are not also redirected (https://cloud.example.com/status.php -> https://example.com/cloud/status.php), *cloud can't access them and doesn't work. There is no way for the extension to find the actual base url with some certainty.

There is a workaround: Users can find out the actual url and configure it in *cloud. But it's easier for users if all urls are redirected. So it would be greatly appreciated if you would do that in your cloud instance (if you have to use redirects at all). Thanks.

Cloud Service Providers

If you run a service based on Nextcloud or ownCloud and would like to offer a branded/tailored version of *cloud for your service, please contact me by email.

Developer guide

The project lives on GitLab: https://gitlab.com/joendres/filelink-nextcloud. If you'd like to contribute to the project, help with testing on different platforms, have a feature suggestion or any other comment, just contact me.

Dev resources