Henk,
The first is from rkhunter since they haven't updated their database and indicated this new version of clamav is secure.
The second message is a bit more strange. Did you configure the server to scan all disks every night? Clamscan is the "disk" scan engine.
I configured the server to scan all users every night. I also get these message when I start Clamscan using the console (clamscan -v -i). Not by email, but in the console of course.
If I don't use the disk scanning option, I don't get the second message.
As far as I can find the message is harmless, and caused by this: PE is the header on dos/windows executables (exe
files). Clam's scanner probably only knows regular dos/windows PE
headers and WindowsCE apparently has a slightly different header (since
it's another architecture).
This gives some more info, and maybe Knuddi understands what to do with it:
http://www.mail-archive.com/clamav-users@lists.clamav.net/msg13989.html