How to set a nFeed field from JEMH?

JEMH is an Enterprise message handler for your Jira, providing a scalable email handling and routing, auditing, incoming mail 'fixing' on the fly, customized notification templates by project, support for email only users, integrated Test Case facilities, Auditing, configuration export/import and more.

nFeed fields are stored in an XML format in Jira database.
To set the default value of a nFeed field from JEMH, we must enclose the value in a XML format:

<content>
    <value>10000</value>
</content>

In the example above, 10000 is the key of the nFeed field (the value stored in the database), not the display value.