So earlier today, I started getting complaints from one of my clients that their customers or admin staff are not receiving any emails from the application that I work on for them. All of the emails had suddenly stopped without any change in the respective code that handles sending emails.
The application runs on Coldfusion 11 on an IIS server and uses SMTPGO email service for handling emails. Since, there was no change in code, I was pretty convinced that there must be something wrong with SMTP2GO. I scoured the logs on the SMTP2GO dashboard and found nothing wrong.
I then decided to drop my assumption that their is nothing wrong on the Coldfusion side and started checking the email logs in the Coldfusion Administrator. The logs contained this particular error:-
javax.mail.AuthenticationFailedException: 535 Incorrect authentication data
Then one of my fellow teammates came up with a suggestion that since this pertained to an authentication error, let’s update the SMTP2GO password on the client’s SMTP2GO account and in the application code and see whether that resolves the issue. Voila! That did the trick. Problem solved. The day was saved yet again.
Hope this helps someone who faces a similar issue.