Thanks for posting, here we mainly focus on general issues about Outlook desktop client.
I can´t use Outlook 2016 in Microsoft Remote Desktop on my Imac ore my MacBook Pro together with Mamut Business Software.
What is the exact issue you encountered? Cannot send emails or something else?
Is this a problem that has only recently occurred? Could you work fine using Outlook together with Mamut before? In order to have a better known of your issue, please check if other users in your work environment also have this same issue.
Besides, does this issue only occur when using the specific Outlook 2016 version? It is suggested to upgrade your Outlook to the latest version and see if the issue could be reproduced.
I did some research about using Outlook together with Mamut and it seems that Mamut uses Outlook Integration to send e-mails, right? If so, to confirm if your issue is related to your Outlook, please try to exit other programs, only run Outlook alone and directly add email accounts and send emails in Outlook client to see if the issue can still be reproduced.
Any update of your issue, please feel free to post back.
If the response is helpful, please click "Accept Answer" and upvote it.