weird problem following 4.10-STABLE build....

[John Von Essen]

After upgrading to 4.10-STABLE I have noticed some weird issues with 
email. My remote clients are unable to connect to the mail server, even 
though they can access websites on it. Since they arent even getting to 
the server, the logs show nothing. At first I suspected networking 
issues. I checked everything and there dont seem to be any problems. 
The only thing I changed when doing the upgrade was I increased 
kern.maxfiles to 12288. Also, my top level ISP does not delegate 
reverse authority. So the mail server ip reverses to something else 
when outside my network.

Any ideas?
Thanks
John