So i was thinking about this from a dns perspetive. If you have a dns forwarder can you not configure it to ensure that emails from the local smtp server never leave tour lan?

Having read this whoke thread, i feel its time to drop Portainer. I find it useful to edit the stackfile and do updates, as well as cleaning old volumes and images. Seems like Arcane and Dockhand are the most popular substitutes. Is the migration from Portainer easy?