Jenkins ext-email plugin fails to send email on build success

Question

I have Jenkins version 1.480.3 installed on my machine and Email-Extension Plugin 2.28.

I have configured my jobs on Jenkins and everything works fine except the fin

Answer 1

Today i faced this issue on a jenkins machine that was sending emails just fine till a couple of weeks ago. I turned it on today and it just wont send emails because of "Error sending to the following VALID addresses"

I tried these steps:

1. Made sure I am not attaching any log file in the email.
2. Made sure "System Admin" email has the domain name mentioned.
3. Jenkins was able to successfully send emails to me when i tried it by "Test configuration by sending test e-mail"
4. Downgraded my email ext plugin.

None of the above mentioned steps helped.

Finally i replaced my company's SMTP server with the jenkins default server and it worked just fine. Not sure why this has happened, I need to talk to my IT guys and see if they have enabled any new security in SMTP server.

Hope this helps to people who hit this same issue.

Thanks