Hi @Pimthong, Prapatsorn (Agoda) ,
Welcome to our forum!
Based on my research, when i click the "..." option of the email in the reading pane in New Outlook for Windows, the Translate option is greyed in some emails. But when i double click to open the email in a pop-up window, the Translate option is available.
Please kindly understand that many functions are not designed at present. At present, what I can do for you is to submit feedback for your request and I have post here, and you could vote for it. If you have any suggestions or ideas, it's suggested that you could post here. Hope Microsoft will notice this in the future.
Thanks for your understanding and support!
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