It‘s coming along in Thunderbird, they continuously mention it in their monthly development blog.
Exchange Web Services support in Rust
November saw an increase in the number of team members contributing to the project and to the number of features shipped! Users on our Daily release channel can help to test newly-released features such as copy and move messages from EWS to another protocol, marking a message as read/unread, and local storage functionality. Keep track of feature delivery here.
If you aren’t already using Daily or Beta, please consider downloading to get early access to new features and fixes, and to help us uncover issues early.
Like others have mentioned, change your provider. Prices are going down again, as there have been advancements on installing renewables. Energy prices at the end of 2024 were 30,5% cheaper than at the start of 2023 (Source. This is the case even though we are paying more for the modernization of the grid, because renewables are that much cheaper than other sources.