Overview

Customers may experience issues with sending emails from their Kerio Connect system after migrating it to Amazon Web Services (AWS). Despite having a valid license key, emails may not be sent out, an issue that is not limited to mobile devices.

Solution

This issue is often due to AWS EC2's default restriction on port 25, a common measure implemented by AWS to mitigate spam.

To resolve the issue of not being able to send emails from the Kerio Connect system after migrating it to AWS, you need to request AWS to lift the default restriction on port 25 for your EC2 instance. Here are the steps to follow:

1. Visit the AWS Knowledge Center article on EC2 port 25 throttle:
   https://repost.aws/knowledge-center/ec2-port-25-throttle
2. Follow the steps outlined in the article to contact the AWS support team and request them to lift the port 25 throttle for your EC2 instance.

After submitting the request, monitor the situation and wait for a response from AWS. Once AWS has lifted the restriction, your issue should be resolved.