JIRA Service Desk 3.5.x release notes
Non-customer comments
In previous versions of JIRA Service Desk, when a person who was not already a customer or participant on a request replied to an email related to an existing request within that service desk, that reply would create a new request. This could be confusing for both the customer and the agents involved in the request.
We've now added an option on the Email requests page which allows the service desk admin to decide if they want to allow non-participants and external people to comment on existing requests via email. When enabled, and if your service desk allows public sign-up, we'll add the comment and create a customer account for the email sender. If public sign-up is disabled, we'll disregard the email.
Creating customers from email address lists
We've added another option on the Email requests page that allows you to choose how JIRA Service Desk creates customers from the To and CC fields of emails.
This features works together with the non-customer comments feature to give you more control and flexibility on who can do what in your JIRA Service Desk instance. To navigate to the setting, select 
> Applications > JIRA Service Desk > Email requests.
Resolved issues
Performance issues
We’ve noticed that versions 3.5.1 and 3.5.2 have performance issues and show errors while opening pages or finishing some actions. This applies only if you’re using postgreSQL and have more than 500k users. To work around it, increase the heap size by 1GB per million users. We’ll release a fix for this in the next bugfix release.