Your software
My Mautic version is: v6.0.2
My PHP version is: PHP 8.1.2
My Database type and version is: MariaDB 10.6.22
Your problem
My problem is: Unable to authenticate Postal SMTP with Mautic v6.0.2 despite correct credentials and open ports
These errors are showing in the log:
Failed to authenticate on SMTP server with username “epostal” using the following authenticators: “CRAM-MD5”, “LOGIN”, “PLAIN”. Authenticator “CRAM-MD5” returned “Expected response code “235” but got code “535”, with message “535 Denied”.”. Authenticator “LOGIN” returned “Expected response code “235” but got code “535”, with message “535 Invalid credential”.”. Authenticator “PLAIN” returned "Expected response code “235” but got code “535”, with message "535 Invalid credential
Steps I have tried to fix the problem:
I have installed Mautic (v6.0.2) and Postal on two separate domains. After that, I generated new credentials from Postal by using the ‘Build a new mail server’ option and have been trying for days to connect it with Mautic, but I haven’t been successful. I have tried with the help of Google, ChatGPT, and Deepsheep, but I still haven’t found a solution.
For this setup, I’ve taken a VPS from OVH, and the necessary ports (including 25) are open. I can send emails using swaks from the terminal, as shown in the screenshots attached to this post. However, the connection still fails in Mautic.
After entering the Postal credentials in Mautic’s Settings under Configuration => Email Settings => Email DSN and clicking Save, the following error message appears when I click on Send Test Email
