hey Alesandro,From my experience so far, "All contacts" is tricky since it's "looking" everything on Contacts level - so, even tho you've put trigger "Interaction X", system is checking if user had that certain interaction, regardless of when it happ...
hey Saravanakumar,regarding "you can add an additional filter for Campaign ID in segmentation so that
contact which has received a mail from this particular trigger campaign
should not get an email again." - what if we want action from trigger-base...