Hi, I am facing problems with open rates. I used in the past sparkpost, sendgrid, amazon ses, elasticemail. Problem is that in last 2-3 months openrate decreased drastically. I'm sending loans/insurance campaigns. Until september i had with amazon ses 10-15% openrate, even 20%. Now openrate hardly increase more than 2%. All lists i send are cleaned. What is the reason for the openr ate decresed? Have spam organizations and yahoo/gmail/hotmail made some security updates?