iCloud and Thunderbird Sent eMail Problem

[UmbraDiaboli]

Hello Everyone,

When I send iCloud emails from my Thunderbird client, these emails will not save/appear on the sent iCloud folder (when you access iCloud from safari). Therefore they will not appear on my other devices (iPhone, iPad, etc). They do, however, save on Thunderbird's save folder.

Is there any setting or something I'm missing?

Cheers,
Umbra Diaboli