We have configured the Our Test Portal server to use our SMTP host as per the documentation.

https://docops.ca.com/ca-api-developer-portal-enhanced-experience/4-2/en/install-configure-and-upgrade/configure-and-use-external-mail-server

The Portal server IP has been added to the SMTP relay allow list.

However we are unable to send any emails.

The problem is the docker stack needs to be recreated after the portal.properties file is modified

<install_dir>/conf/portal.conf

So that the new parameters (new IP address, or server name of the mail server in this case) flow through to the docker containers and their setup.
 

API Portal 4.2
 

The process to remove the current docker stack and then re-instate it is as follows.  Once rebuilt then the new stack containers have the correct setting for the changed mail server. 

# remove current stack 

docker stack rm portal

watch docket ps   # (until all the containers are closed) 

docker rm $(docker ps -qa)

docker container prune
 

# restart and rerun portal 

systemctl restart docker

cd <portalhome> 

./portal.sh

watch docket ps   # (until all the containers are running)