Dear Atlassian Team,

we would like to submit a feature request regarding user selection in Jira Service Management, specifically for dropdown user picker fields.

Current situation
In our JSM instance, tickets can be created via email. When this happens, Jira automatically creates so-called customer accounts for the sender’s email address (e.g. Gmail or other external domains). These accounts do not consume licenses and have no access to the Jira instance itself, which is expected behavior.

However, all these customer accounts appear in the global user directory and therefore also show up in user picker dropdown fields. As a result, external email addresses (e.g. @gmail.com) can be selected in fields where only internal users should be eligible.

Problem / Risk
From a security and data quality perspective, it is problematic that external customer accounts can be selected in fields that are intended to reference internal employees only. This can lead to incorrect assignments and confusion, especially in configuration or responsibility-related fields.

Requested feature
We would like to have a native option to:

• Restrict user picker fields to a defined subset of users

• Or filter selectable users by email domain (e.g. allow only @gmail.com* or other internal domains)

This should ideally be configurable per field or per project, without requiring custom scripts or third-party plugins.

Context
We are aware that workarounds via scripts or plugins are limited and not always feasible, especially in Data Center environments. A native solution would greatly improve security, usability, and maintainability.

Thank you for considering this request. We would be happy to provide further details or examples if needed.