Here is what is going on. I use mailmeteor to check my copy. I am doing inbox placement testing on instantly. If I write a six grade reading level email copy and don't spintax it. I can get 90%+ in the inbox.
As soon as I spintax it it even minor and check the spintax copy in mailmeteor. I only hit 30% inbox placement test.
Now I can take that same spintax copy with Google inboxes and get 100% inbox on domains that are 21 days old.
I don't get it is anyone having major issues with Microsoft? Mostly Micro to Google inboxes.
My reply rates used to be a little over 3% now .5%