We have 3 instances of TAC on 2 SMTP notification works fine. On the 3rd, we got error. From shell dns (host resolution) and telnet to port 25 works fine. Any suggestion what to check next?
Thank you in advance.
The error shows the the SMTP host unknown, I guess the 3 TAC instances are on different server, are you able to ping to the SMTP host on command terminal from this server?