CausePostfix is used as mail server. If message is sent to several mailing lists at once, it is delivered only to one mailing list.
If several mailing lists are created for one domain and message was sent to these mailing lists at the same time, it is delivered only on one mailing list.
ResolutionThis issue was discovered in Parallels Plesk Panel 9.x.
In order to fix issue apply hotfix on the server. Hotfix can be applied on Parallels Plesk Panel 9.x on Centos5.x and RHEL 5.x
Replace the file $PLESK_LIBEXEC_DIR/postfix-mailman with the appropriate file from the attachment.
Hotfix for Centos 5 x64
Hotfix for Centos 5 x86
Hotfix for RHEL 5 x86
Hotfix for RHEL 5 x64
Set up correct permissions on the file $PLESK_LIBEXEC_DIR/postfix-mailman after replacement.
# chmod 4755 /usr/lib64/plesk-9.0/postfix-mailman
Please read article #8083 about a hot-fix installation procedure.