We have released Email Marketing 5.2.5, which comes with only one major change (along with some minor bug fixes) – the ability to save your API connection details on the subscriber import page for external sources:

If you import from an external source, such as Salesforce, it can be extremely tiresome to re-enter the connection details each time. This should save you a lot of time, and allow you to use the import process more efficiently.
This feature works per user, meaning each user that logs-in to the admin section can have their own API connection details saved, and they will not see the connection details for other users.
We are continuing to improve the subscriber import page, as well as all aspects of our software, so please let us know if you have any questions, problems, or ideas.