Emails only import as headers with no content

After changing from a windows to a Linux server with a version upgrade in the same process - some not all of fetched emails import headers only with no content.  User Name (email) & Subject line are imported correctly but the ticket is populated with what appears to be header information

Mail import has been running both on cron and auto-fetch (which is how it was on the old server) - have just turned off auto-fetch to see if the problem is isolated to one or the other (not hopeful)

Mail via IMAP from GMAIL
PHP Version 5.4.45
Appache Server on linux
OS Ticket 1.9.12