Please kindly understand only English is supported in our forum now, since your question is in Spanish, I will try to understand your issue via machine translation, if there're any misunderstanding, please forgive me and re-edit your issue via English, thanks in advance.
In the New Outlook, the auto-capitalization feature for the first letter of every sentence is not available in the preview version.
Please kindly understand that many functions are not designed at present. To get this feature more quickly, I have found a post in feedback collection website and you could vote for it. Many features of our current products are designed and upgraded based on customers’ feedback. You can also make suggestions on that website and hope Microsoft will notice this in the future. Thank you for your understanding and support.
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