OK Figured it out. There's indeed no need to install VMWare tools on the
FortiMail VM. I just needed to change a setting on the job itself: apart
from disabeling VMWare tools quiescence I also disabled
application-aware processing. Backup job now run...
I have the same config as topic starter. I also would like to backup the
FortiMail VM using Veeam, therefore the use of VMWare tools is a
necessity. Also on behalf of the topic starter I would like to repeat
the question: are there any guidelines as ...