Mail Sending to External domains about copper HOT 3 CLOSED

copper email solution used port number 25 for smtp mail sending.
But GCP has blocked port 25 for mail sending.
https://cloud.google.com/compute/docs/tutorials/sending-mail/

So it is good to up the system with port 465.
We are working on it now.

from copper.

GCP had proposed to use NAT to use another port like 465 and 587 instead of 25. But the issue is our kubernetes cluster has loadbalancer type service which is opened to internal. This is not the NAT implementation architecture. Other option GCP had proposed is mail relay. There are free mailrelays we can use our perpose until we build our own one.

from copper.

We could complete mail sending to external domain using a external mail rellay only. When we try to communicate with standard email ports with external mail servers those outbound traffic is blocked in GCP. So we configured our own mail relay in AWS and connected with it from port 2525. Now external mail sending is ok .

from copper.