Thank you for considering Aspose.Email for Java.
1. Aspose.Email for Java doesn’t have dependency on any other platform, though it is auto ported from its .NET equivalent version
2. Yes, it runs on JRE 1.6
3. You can easily convert a MSG from an EML file. Please have a look at this ready to run sample
for your kind reference
4. Yes, Aspose.Email for Java allows you to create PST from MSG files as you can see from this sample
You can try Aspose.Email for Java without any limitations by getting a 30 day temporary license
before purchasing it and refer to our online documentation guide
for further information about the features supported by Aspose.Email for Java API. Please let us know if we can be of any additional help to you.