Issue Summary

Currently, when having a custom email address connected to a JSM project for incoming email requests, the email handler reads all the email messages from there in order to process the messages.

However, there are scenarios when it's expected that an email won't create a new ticket, for example, when self-signup is disabled or when the sender doesn't have an approved domain:

After this happens, the email processor leaves the message as read, causing confusion on the customer side as it is a custom email address account.

Steps to Reproduce

1. Have a custom email address connected to a JSM project's email handler.
2. Configure a restriction, like an approved domain in the Customer Access section.
3. Send an email from a non-approved domain to the custom email address.
4. Observe that the ticket creation will fail, as expected. However, the message in the custom address will be left as read.

Expected Results

If the email is read and is not processed by the mail handler for an expected reason, then it should mark the email as unread again.

Actual Results

The email handler reads the email messages and leaves them in that state even if it decides not to process them.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available