Sendmail via SMTP from off SMTP server subnet problem.
Mac OS X Server 10.6.8 used as mail server. Port 25 is open to both the inside and internet networks. Mail server is set to allow relay from all of our private subnets including VPN network below.
Mac OS X 10.6.8 clients running FileMaker Pro 11.
Some clients are on the same subnet as the server.
Some clients are at remote locations which use either site to site VPN and direct VPN for network connection. Port 25 is forwarded to the mail server.
Mail clients are able to access and send mail from internet, local network, and remote network without trouble.
DNS resolves the same for the mail server from both inside the private network and on the internet.
Set up a script to send email via SMTP. Email sends as expected from computers on the server's subnet, but does not from the remote subnets.
Settings and testing :
SMTP in the script is set up as port 25, TLS, Cram-MD5. These settings work with our Mail clients and cell phones from anywhere.
When changing from TLS to SSL the error changed from "email could not be sent" to "there was a problem with SSL."
I have assumed that there was a network issue but am running out of adjustments to try. I am leaning towards FileMaker due to the fact that if I convert the script to Email Client, the client sends properly with the exact same server settings for SMTP.
We have not made any changes to the network itself. We have updated FMP and FMSA to the most recent versions. This script did work at one time but I do not know when it stopped.
I assumed possible script corruption and tried a new database with only enough content to test this issue with no change in result.