org.apache.james.transport.matchers.SizeGreaterThan Checks whether the message (entire message, not just content) is greater than a certain number of bytes. You can use 'k' and 'm' as optional postfixes. In other words, "1m" is the same as writing "1024k", which is the same as "1048576".
org.apache.james.core.MimeMessageWrapper This object wraps a MimeMessage, only loading the underlying MimeMessage object when needed. Also tracks if changes were made to reduce unnecessary saves.