Disable TNEF as standard
As Apple refuses to support TNEF there is a constant issue with sending attachments a.k.a winmail.dat. It utterly ridiculous that Microsoft and Apple won't get together to sort this out.
As you won't, O365 and Exchange in general should default to not using TNEF as standard. Then it won't be an issue for 99.99999% of tenants. Those who actually care about this can go in and enable it if desired instead of requiring the majority to go in and disable it.
is there any help here? how to get easily OFF this TNFE, our customers also can't open attachments
because they are gettin WINMAIL.DAT file.... and this wasn't problem before
It's not just Apple ... no-one aside from Microsoft supports TNEF / WINMAIL.DAT. According to this comment - https://support.microsoft.com/en-us/help/2487954/how-to-specify-the-email-message-format-that-s-used-for-external-recip - Office365 appears to have changed the default back to TNEF some time in August 2019. That matches our experience - we process PDFs attached to emails and have started getting WINMAIL.DAT again, after years of not seeing it very often.
Seriously, Microsoft, WHY?????