I have an Exchange 2013 full service packed and running well, apart from emails to gmail.
We are getting delays of up to 24 hours due to gmail thinking we are a bulk sender and not complying with their guidelines.
I have checked the logs and cannot see any sign of bulk email or spam heading to gmail and i have also ran as many checks as i possibly can and all come back saying the server is fine.
We do not get these delays emailing anyone else.
Im really not sure where to go with this as users are getting unhappy (quite rightly) and im not sure what else i can do.