My emails sometimes show as weird "From" address to recipients

Hi,

I am using Office 2019 Home and Business at work and sometimes my recipients receive my mails from a weird email address, not mine. something like outlook_29FKLG@outlook.com.

My email address is my.name@company.com

I've seen this official article from Microsoft about a known issue that describes exactly what seem to be my issue:

https://support.microsoft.com/en-us/...d-a3b79ea4eafd


But, in this article, they say it's only if i connect my "Outlook.com", and in this case I have my company's domain, and the server is not connected to Office365, it's a standalone Exchange server of our company.

How can I check if there's nothing malicious that is causing this issue? These are sensitive emails

And also it's written that they're actively working on it but the last updated it in 2018.. so they just left it like that? No fixes?

Bump