Please see the last HN thread I linked for a discussion of headers: https://news.ycombinator.com/item?id=19100332 https://news.ycombinator.com/item?id=19100332

Please see the last HN thread I linked for a discussion of headers: https://news.ycombinator.com/item?id=19100332 https://news.ycombinator.com/item?id=19100332 As mentioned there, the "via" most likely comes from the fact that the recipient address is a Google Groups address that multiple people can receive. Also, as mentioned in the Github issue, Google's G Suite security staff has checked the headers (in the Paypal case) and come to the conclusion that nothing is wrong with them, and that it's a Gmail issue (and that the fact that the recipient is a Groups address should make no difference for spam filtering).