Thunderbird Offline Mode

[AnanasPfirsichSaft]

If I start in offline mode OR switch to it, the DKIM verifier states that it cannot connect to the DNS server. Even if I put Thunderbird back into online mode.

Maybe this can be fixed that the verifier starts working again when I return to online mode?

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Thunderbird 60.2.1 (Ubuntu Bionic [18.04LTS]) and DKIM Verifier 2.0.0

[lieser]

Until a proper handling of the offline mode is added, you can enable the extensionsdkim_verifierdnsjsdnsautoresetserveralive-boolean setting as a workaround. Note that this setting is not exposed in the settings window of the add-on. You will have to change it via TB's config editor (TB Options > Advanced > General > Config Editor).

[AnanasPfirsichSaft]

With this setting, it resets the DNS server "back to alive" in offline mode, but cannot connect to the nameserver again.

authResult: ({version:"2.1", dkim:[{version:"2.0", result:"TEMPFAIL", sdid:"xxxxx.de", auid:"newsletter@xxxxx.de", selector:"mailjet", errorType:"DKIM_DNSERROR_SERVER_ERROR", res_num:20, result_str:"Fehler bei der Verbindung zum DNS-Server", favicon:(void 0)}]})

But this is not urgent. It can be mitigated by storing the verifier results until the next online session.

EDIT: If you use libunbound, it also works offline. The wiki explains how to do it.

[lieser]

Note that the default JSDNS resolver uses Thunderbird for the network communication. As you are in offline mode, network communication is disabled by Thunderbird itself (connection fails with NS_ERROR_OFFLINE (804B0010)). This behavior can probably not be changed.

As libunbound uses the underlying OS directly for the network, it is not affected by Thunderbird's offline mode.

If you are often in offline mode, I would recommend you to enable the caching of the DKIM keys, if you haven't already.

[lieser]

Still have to actually test it but seems like the navigator.onLine property and the online/offline events could be used to implement this.

[lieser]

The addon now detects if Thunderbird is in the offline mode and if it goes back to online. This means for both DNS resolvers:

• No DNS queries are done if Thunderbird is in the offline mode
• DNS configuration is reset after Thunderbird goes back online