Thank you for writing to Aspose support team.
Could you please provide more details about the server you are connecting to? I have tested this scenario by connecting to a POP3 server using the latest version of Aspose.Email for .NET 4.8.0 and it works fine. I would request you to please provide us with a test account credentials in order to test this issue at our end and assist you further.
I can confirm that in last version (4.8.0) is problem fixed. We used old library.