Hi @Rrrachana
When I open the link you shared, there is 404 error.
If you share the OneDrive links for these m4a audio files via emails, will they play properly on mobile phones? You can troubleshoot by opening the email in your browser and mail app.
I suggest you convert m4a files to other Audio files, such as MP3, for a check, as not all Android music players can support it, or there are some limitations on the mobile phones, browsers to play.
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