Microsoft Outlook Keeps Freezing When Forwarding Email

A variety of issues can cause Outlook to freeze when forwarding email, including a bug within the software, a conflicting program or add-on, a corrupted email archive or a problem with the individual message itself (more likely if you are only having problems forwarding one email in particular). Make sure you have installed the latest updates for Outlook before attempting any other troubleshooting steps.

Program Bug
If part of Outlook's program code has become corrupted or developed a fault, this can cause freezing issues. Downloading and installing the latest updates from the Office website, or uninstalling and reinstalling Outlook from scratch, should be enough to resolve this issue. Uninstalling and reinstalling Outlook shouldn't affect the messages in your email archive, though it's always wise to make backups in case (or connect to a Web service such as Outlook.com via IMAP). The process should reset Outlook's settings and entries in the Windows registry settings file, too.

Corrupted Data
If Outlook comes across a corrupted piece of data that it can't parse -- whether in your user profile, the email archive or the folder you're viewing -- this can cause a hang. Running the Inbox Repair tool (the scanpst.exe file in the Outlook installation folder) or the Fixit tool from the Microsoft Support website may be enough to resolve the issue. Alternatively, you can try creating a new user profile from the Account Settings dialog (choose "File" then "Info" from inside Outlook). Reducing the size of your inbox by moving messages into smaller folders can also help.

Related Reading: Outlook Freezes When Typing

Conflicting Program or Add-on
An Outlook add-on or third-party program can be causing the freezing issue. For example, your security software may be attempting (and failing) to scan the outgoing email for potential threats as you try and forward it. Check that your installed security tools are up-to-date, and look within these programs for options related to email scanning and checking. You may need to disable certain settings for the email to be successfully sent. The list of current add-ins can be viewed by selecting "File," "Options" and then "Add-Ins" from within the software. From the same dialog, you can disable these plugins one by one to see if the problem is resolved.

Other Issues
It's possible that something within the email itself is causing the freezing issue, particularly if you only have trouble with one or two specific messages. Converting your message to plain text before forwarding it (via the "Plain Text" option under the Format Text heading on the message window) may help by eliminating images and other interactive elements from the email. Removing and re-adding the email account you're using (via the "Info" tab on the File menu) or creating a new user account within Windows can also help to resolve problems with Outlook freezing.