One of our Odoo 11 hosting users reported issues with freezing screens.  They would for example click on a help desk ticket and it would freeze. Our technicians looked through the Odoo logs, NGINX, and PostgreSQL.  We resolved some minor issues reported in those logs but none of that seemed to resolve the issue.  After much more trouble shooting we found that this seem to happen when Odoo was sending email.  We figured out that the email was delayed and sometimes not connecting.  This server is a container running on an EC2 instance sending emails through AWS SES on port 25.  We checked the security groups and they all looked fine.  Changed the connecting port to 587 because of the limits "Throttling"  Amazon puts on port 25.  Issue resolved.   Wanted to post this blog to hopefully save someone from the hours of troubleshooting we did to resolve this issue.

    BeCloud is a premium IT management firm with locations and capabilities throughout the United States.  We partner with Amazon Web Services to provide best in class efficiency, scale, and affordability.   If you need assistance getting the most out of your Odoo installation please do not hesitate to contact us.