Some attachments are being sent as WINMAIL despite plain text switch - Microsoft Community

microsoft team,

some of recipients receiving pdf attachments winmail files on phone only. on desktop fine. i've read forums, tried plain text changes, yet still receiving phone files winmail. appreciate help. have read responses , have tried changes recommended it's not helping. 

thanks. 

1 cause message format stored in autocomplete list. fix, start typing in address, select , delete auto complete list. retype or select contacts.
deleting entry autocomplete list fixes it, if not, have other solutions @ https://www.slipstick.com/problems/outlook-is-s..., including ability disable using rtf (but can affect features, such voting or task assignments).

Office / Outlook / Other/unknown / Office 2016