After upgrade from Parallels Plesk Panel 9.0.0 update1 to 9.0.0 update2 mail message headers have incorrect structure
After upgrade from Parallels Plesk Panel 9.0.0 update1 (release) to Parallels Plesk Panel 9.0.0 update2 (package psa-hotfix4-9.0.0) mail message headers have incorrect structure.
Package psa-mail-driver-common is not upgraded and so the old version of binary file $PRODUCT_ROOT_D/handlers/hooks/spf is used for messages processing.
You should upgrade package psa-mail-driver-common manually to resolve the problem.
Package for Parallels Plesk Panel 9.0.0 update 2 is psa-mail-driver-common-9.0.0-OS.build90081222.11. The packages is located in /opt/maildrivers of Parallels Plesk Panel 9.0.0 distributive.
You may download the package appropriate for your operating system and architecture from the autoinstaller website http://autoinstall.plesk.com/.
For example for CentOS 5, 32-bin the package is located in http://autoinstall.plesk.com/PSA_9.0.0/dist-rpm-CentOS-5-i386/opt/maildrivers/
Download the package and install it with rpm -Uvh (for RedHat family) or with deb -i (for Debian and Ubuntu).