I've encountered another problem. If I leave it as is, it mills fine, then gets more herbs from mail, and if I follow instructions in the profile description, by making postal addon to keep 2 free empty slots in bags, it will get the mail, then start milling, while still standing at the mailbox, and keeping adding up more herbs, as the bags get empty. Having enough herbs in mail, I got into situation, when all normal bag slots get filled, and herbal bag gets empty, but postal counts those slots as normal too, so it fills all normal bag slots, and milled herbs just get destroyed. I think the way to fix this, is to make toon move away from the mailbox, as soon as bags get filled and ready for milling. THanks.
P.S. Actually, it just keeps milling even after bags are full, destroying all the herbs left. Profile is unusable atm.