Email succeeds on one server but fails on other

[faisalchishti]

We are using Docker and one of my flow uses node-red-node-email node to send out an email after a certain action. The email node works good in our dev environment but does not work in production (Same image is pushed to couple other servers that serve as production)

Error:

Error: Invalid greeting from server:
421 4.3.2 Service not available: 421 4.3.2 Service not available

Using smtp on port 25 without SSL.

[{"id":"9d9d4870.a1cce8","type":"e-mail","z":"958f5a0e.571f38","server":"smtp.abc.xyz.com","port":"25","secure":false,"name":"","dname":"","x":1291,"y":2066.444580078125,"wires":[]}]

Please note that this was working earlier and stopped working all of a sudden. I am absolutely clueless. Any inputs? @knolleary

[edje11]

SMTP error 421 is not a specified error, it's more an randomly used error.
Check with your provider what this error means.

[faisalchishti]

@edge11 It was indeed an internal issue. The service had been deactivated. Thanks.