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.
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Thunderbird: 68.2.1 or newer
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An account on a server running a supported version of Nextcloud or ownCloud, more specifically:
- Nextcloud version 30 or newer (older versions might work, but are not supported by Nextcloud)
- ownCloud version 10.0.10+ (10.0.9 and older versions contain bugs that prevent *cloud from working).
- ownCloud Infinite Scale version 5 or newer (older versions might work, but are not supported by ownCloud)
If you can't or don't want to run your own server, there are many offers for hosted Nextcloud and hosted ownCloud services.
- Go to Preferences -> Compose -> Attachments
- Click the link "Find more providers..." at the bottom of the page.
- Find *cloud in the list and click the "Add to Thunderbird" button.
- On the "Options" tab click the button "Add *cloud".
- Configure. Only three settings are strictly necessary:
- Server URL
- Username
- App token or password
*cloud is also available via Thunderbird's Add-on repository:
After you have configured at least one Nextcloud or ownCloud server there are three ways to start the upload:
- Add an attachment that is larger than the upload threshold. Thunderbird will then show a yellow notification bar at the bottom of the message window with a "Link" button. To get this button for smaller attachments you can change the threshold: Go to Preferences -> Compose -> Attachments and change the value "Offer to share...".
- In the message window in the attachments menu (downward arrow in the "Attach" button), there is an entry "Filelink". It lets you choose a file and uploads it immediately.
- After you added an attachment you can choose "Convert to..." from that attachments context menu (right click on the attachment).
If you share a file that has
- the same name and
- identical size and
- identical modification time (to the second)
as a file that has been shared before, *cloud considers this to be the same file and does not upload it again. Instead, *cloud creates a share link to the first file.
If you've got files that are the same in these three ways but have different content, this can lead to the wrong file being shared. This could happen, for example, if you use a program that generates several files in different folders quickly.
At the moment, the only thing you can do is change the file names or set different modification times (use the 'touch' command on Unix systems).
In some minor versions of Thunderbird 102.2 filenames with specials characters or in non-US script systems like Greek case problems. The upload works, but sharing the uploaded file fails. This is fixed in Thunderbird 102.5.0; please update Thunderbird.
Many users would like to change the text that is inserted into the message along with the download url, eg add the expiration date, change the cloud service link, remove some of the text or style the HTML less prominently. Addons like *cloud have no chance to do that, because the template text surrounding the url is part of Thunderbird. The Addon only supplies the url, Thunderbird wraps its template around it and inserts the whole thing into your message (technical details here and here).
There was a bug in Thunderbird: If you attached a file from a network share, it was uploaded to the cloud and the share link was inserted into your mail, but the file was also attached to the message. This was fixed in Thunderbird 68.11.0 and 78.0.1. If you're still experiencing this issue, update Thunderbird.
In some situations the url you use to access your Nextcloud/ownCloud account in the browser doesn't work as the server URL in *cloud.
If your access url is redirected to the actual cloud location (plus some technicality), *cloud can't find the actual url.
If this happens to you, point *cloud to the actual cloud location:
- Open your cloud in a browser.
- Log in.
- Depending on your cloud version you now have different views:
- In Nextcloud 20 and newer you see the "Dashboard", just continue to the next step.
- In older versions of Nextcloud and in ownCloud your see the "Files" app. Continue to the next step.
- If you are neither in the "Dashboard" nor the "Files" app, click on the folder icon in the cloud's top menu to go to the "Files" app.
- Copy the complete url from the url bar of your browser
- Paste it into the server url field in *cloud's configuration (in Thunderbird).
As soon as you save the settings, *cloud will remove unnecessary parts.
If the admin of your cloud used something called a "self signed certificate", Thunderbird (not *cloud) refuses to connect to the server. There are two solutions:
- (preferred) Tell your admin about the problem. She might install another type of certificate, which Thunderbird accepts.
- (if 1. is not possible) Force Thunderbird to accept the certificate:
- Open Thunderbird's preferences
- Go to "Privacy & Security"
- Scroll down to "Certificates"
- Click on "Manage Certificates"
- Choose "Servers"
- Click on "Add Exception"
- Enter your cloud's address in the "Location" field
- Click "Get Certificate"
- Click "Confirm Security Exception"
The download password has to comply with all the rules for passwords on your cloud, otherwise the upload will fail. There are default rules of Nextcloud and ownCloud, and your admin might have configured some different rules.
This is usually caused by a misconfiguration of the cloud server. Please point your cloud admin to the section on Apache and mod_rewrite below.
If things still don't work, I'd appreciate a problem report by email. Thanks.
If you use download passwords, don't put them into an email, but give them to the recipient via a separate, secure channel eg a messenger or a telephone call.
Why? As a security measure the generated download links contain a long, almost random part. So an attacker (let's call her Eve) can't guess the link for a file or scan all possible links to find a file. The only reasonable way for Eve to gain access to your file is to intercept the email. (If you are interested in technical details, read this posting).
So the links are fairly secure by themselves and quite comfortable for the recipient, because she only has to click the link.
If you use download passwords, never put them into the same email as the link. Because if Eve can read the link, she can also read the password. So a download password in the same email doesn't make the transfer more secure, but only more complicated for the recipient. The same goes for a separate email with the password: If Eve can intercept the first email with the link, she is very probably also able to intercept the second email.
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:
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If you are using Nextcloud or ownCloud: Open your account in the browser and go to Settings -> Security -> App Token and at the bottom of the page generate a new token. Copy&paste it into the "App token" field of the Attachments preferences page in Thunderbird.
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Only if you are using Nextcloud: Type your user password into the Attachments/Outgoing preferences page in Thunderbird. Upon saving, the Add-On will try to get a token from your Nextcloud and use it instead of your password. You will notice the change, because afterwards the password field is filled with dots completely (app tokens are quite long).\
If you attach a file that's already in the attachments folder in your cloud with identical contents, that file is not uploaded again. Instead the existing file is shared.
To make this possible, *cloud never deletes files in your cloud. Over time your attachments folder may grow to considerable size. It's safe to delete old attachments. Your admin may automate that, using "Flows" in Nextcloud or ownCloud.
You can use this behavior if you want to share large (or many) files: Sync your attachments folder to a folder on your computer using the desktop client. If you then attach a synced file from your computer to a message, *cloud will notice that it's already uploaded.
If you attach a file with the same name but different contents as a cloud
file, the cloud file will not be overwritten. Instead *cloud moves the
existing file to a subfolder of the attachments folder; the original share
link will remain valid and point to the old content.
Then the new file is uploaded and shared with a new share link.
*cloud uses a similar method as the Nextcloud/ownCloud desktop clients to decide if the local and remote files are identical:
- identical name and
- identical size (in bytes) and
- last modification within the same second.
Some settings in Nextcloud/ownCloud are relevant for this Add-On:
- Settings -> Sharing -> Allow apps to use the Share API has to be enabled
- Settings -> Sharing -> Allow users to share via link has to be enabled
- The app "Share Files" has to be active. In ownCloud the Apps management is part of the administrator's settings, in Nextcloud it's accessible directly from the admin's profile menu.
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.
By default Thunderbird (not *cloud) refuses https connections using self-signed certificates. It's a lot easier for your users, if you install a Let's encrypt certificate. There are great How-tos on their site.
Nextcloud andownCloud both require mod_rewrite to be active if run in the Apache http server. Without mod_rewrite *cloud fails with different error scenarios depending on other details of the configuration.
Currently *cloud only supports HTTP Basic Auth. In ownCloud Infinite Scale (oCIS) Basic Auth is disabled by default and has to be enabled.
- Johannes Endres, initial implementation, maintainer
- Josep Manel Mendoza, Catalan and Spanish localizations
- Gorom, French localization
- Jun Futagawa, implementation of generated random passwords
- Lionel Elie Mamane, solution of the LDAP/getapppassword problem
- Óvári, Hungarian localization
- Pietro Federico Sacchi, Italian localization
- Asier Iturralde Sarasola, Basque localization
- Anatolii Balbutckii, Russian localization
- Aleš Petržík, Czech localization
- mixneko, traditional Chinese localization
- Based on FileLink Provider for Dropbox by Geoff Lankow
- Inspired by Nextcloud for Filelink by Olivier Paroz and Guillaume Viguier-Just.
- Thanks to @JasonBayton for his Nextcloud demo servers of many (old) versions, that helped in the initial testing a lot.
- Contains punycode.js, Copyright Mathias Bynens, MIT license
- Contains photon-components-web
If you'd like to contribute, see CONTRIBUTING