While I believe email engagement algorithms at Gmail goe far deeper than these two experts, I do want to preserve these two posts and link to them just for my own enlightenment and reference.
Hope you enjoy them as well.
Andrew Barrett of the “Email Skinny” blog goes on the note 7 major engagement indicators of quality that Gmail uses front and center.
3.Move to junk (BAD)
4.Not junk (GOOD)
5.Delete without open (BAD)
6.Move to folder (GOOD)
7.Add to address book (GOOD)
Julia Peavy of Return Path talks here about “Winning back” an unengaging list.