New-MailboxExportRequest -ContentFilter {size -gt 10KB} Invalid filter syntax

Question

I would like to export massages of a mailbox, where mail item or attachment or anything is larger then XXKB
New-MailboxExportRequest
-Mailbox "User1"
-FilePath "\\server1\pst\User1.pst"
-ContentFilter {size
-gt 10KB}
The provided ContentFilter value is invalid. ContentFilter is invalid. Invalid filter syntax. For a description of
the filter parameter syntax see the command help.
"size -gt 10KB" at position 12. --> Invalid filter syntax. For a description of the filter parameter
syntax see the command help.
"size -gt 10KB" at position 12.
+ CategoryInfo         
: InvalidArgument: (size -gt 10KB:String) [], ContentFilterInvalidPermanentException

Answer 1

Build is CU5.
I did not try other parameters.  I`m looking how to find and remove e-mail massages grater then 25MB, because users do not clan there mailboxes. They ignore warning, ect. And to cover my »arsh«, priory moving massages to O365, i will do
export to PST, then delete and delete dumpster.  But simple task like mailbox search, eDiscovery does not 
search  by size.
That does not work eider :
-SearchQuery "Size -gt 2024KB"
"Size > 1024KB"
'Size:>1024KB'
"Size:>1024",