New Seafile Add-In for Microsoft Outlook ready-for-testing

Integrate your favorite File Collaboration solution Seafile and Microsoft Outlook with the new Seafile add-in for Microsoft Outlook. A ready-for-testing version is now available for download at The add-in was developed by datamate, European Seafile Partner, and freelance developer Simon Giesen.


The add-in supports:

  • Create sharing links (with password/expiration) directly from the mail window
  • Insert existing sharing links in emails
  • Upload file attachments to a folder/library
  • Upload an email’s as an HTML file to a folder/library
  • Switch to Seahub with one click - no login required

Authentication with username/password and single-sign on (SSO) is supported. The password/token is stored in a JSON-formatted cfg-file in Windows’s hidden AppData folder. (Depending on the system’s configuration, the file is either saved in the Roaming or Local folder.) The password/token is protected with .NET’s DataProtectionProvider Class against the Local User Windows Certificate. The file itself is unencrypted.


The add-in is compatible with Microsoft Outlook 2010 and later as well as Office 365. The add-in was tested extensively on Windows 10 computers.

Extract the files from the package and run the setup.exe. If not already installed on the computer, the .NET Framework 3.5 is installed as the only prerequisite.

Further development and release

The add-in is version 0.9 and under development by datamate. At this point, the upload of emails and email attachments still requires a local folder at C:\seafile. The English translation is WIP.

The test period runs for 2 weeks. Post you feedback underneath. A production ready version will be released under an open-source license in the weeks thereafter on GitHub.

datamate considers developing an enterprise-ready add-in supporting custom branding and automatic deployment. Interested? Please contact us at!


Hey, this sounds awesome.
Unfortunately, it won’t work in my setup. Installation runs fine but I can’t login to my server (wrong credentials).

Looking to my nginx error.log I can see some SSL handshake issue.
2020/03/28 10:47:35 [crit] 1299#1299: *49056 SSL_do_handshake() failed (SSL: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol) while SSL handshaking, client:, server:
My server is configured to SSLlab’s recommendations and achieves a solid A+ there. Let me know if you need any config details (only TLS 1.2 and 1.3 enabled).

Thanks for this feedback. We will look into it. I know that our test instances also support TLS 1.0 and TLS 1.1.

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