Why Outlook Mail on Windows 10 Mobile is trying to cipher every e-mail?

[Misieq]

I have an EAS account added at my Lumia 650.
Before updating Outlook Mail my account work perfectly fine.

However after update (I am not sure if app update or AU update - both were done at the same time) Outlook Mail is trying to cipher every e-mail I want to send.
Each new e-mail has icon of "lock" at subject line.
Of course in settings S/MIME is deactivated for both signing and ciphering.

From that reason I am not able to send e-mail because client is complaining that there are no public keys for receipients.
Any hint if this is some problem of new version or anything else?

 

[Chintan Gohel]

I can suggest the usual method of removing the account and adding it back

 

[Misieq]

To be honest I even resetted phone to factory settings and re-added account.
Problem still occures.

 

[Misieq]

Looks that it is fault of "Outlook Mail" app.
I used WDRT to rollback to Threshold. All worked fine till Windows Store has updated Outlook Mail app.

 

[Chintan Gohel]

Looks that it is fault of "Outlook Mail" app.
I used WDRT to rollback to Threshold. All worked fine till Windows Store has updated Outlook Mail app.

so you already updated the app? I would have suggested holding the update - don't enable auto update of apps