We have Apache reverse proxy setup and working with 6.5.x. After the upgrade to 8 it broke. If we replace the forms8.nsf with forms6.nsf it works again. What might the difference be between forms8 and forms6 which would prevent this from working.
Subject: Too little information
Which mail template are you using?What is in the error log of the apache server?
Apache is not a supported web proxy in front of Domino as far as I know. IBM Http Server (sort of apache) + WAS Plugin is.