We understand that GMAIL has functoinality that inspects email sent bia Marketo and displays a text "mkto" in an email header.
Is it possible to prevent this? I do not want recipients see this. Plus I think other MA products have the same problem.
Some people say it can be solved by configuring SPF/DKIM and others not...
Also some people advise it depend on where our instances locate on? It sounds so confusing...
Hopefully I could get advice from those who have in fact solved this problem.
p.s. I attach a photo for details.