But there are good news. Gmail improved the conversion to HTML for Microsoft Office documents and the images are no longer ignored. You can also read the entire documents, without having problems with unexpected truncations. I tested this with a 3 MB document that included seven graphs and it was converted almost flawlessly.
I wonder why it took so long to improve the conversion and why other file types continue to be handled rather poorly.
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{ Thank you, Azwandi.}