Try This:
1. Start Outlook in safe mode then print<start->run->outlook /safe> [it can disable 3rd-party Add-ins temporarily]
2. Try to send affected user two mails which contain only text content, then print both for narrow down cause
3. Copy those unprintable mails to a PST, then move it to a testing PC which is fine with print multi-mails function, see if you can reproduce the issue. If you can, we’re able to narrow down the cause to the mails themselves
Workaround:
1. Does there have unopened HTML formatted message in those unprintable mails? If so, see KB 301910
2. Do those unprintable mails contain HTML content? If so, see KB 831608 (It must download content if you want to print a message that contains blocked content)
3. Check unprintable mail’s “Message Class”, change it to IPM.NOTE if it’s not before
a. Run MAPI Editor->”Session” menu-> Logon and Display Store Table->choose your mail profile (this will not appear if you only have one profile)->Right-click the one that display name column shows “Mailbox-your name”->choose “Open Store”
b. Now in the second window, expand “Root-Mailbox”->expand “IPM_SUBTREE”->Double-click “Inbox”
c. In the third window, check “Message Class” column of unprintable mail
More Help:
http://support.microsoft.com/kb/301910/en-ushttp://support.microsoft.com/kb/831608/en-usDownload MAPI Editor
http://www.microsoft.com/downloads/details.aspx?FamilyID=55FDFFD7-1878-4637-9808-1E21ABB3AE37&displaylang=en