Your post is wonderfully UNINFORMATIVE. Does this
The same jcl was working earlier.
mean the JCL was working BEFORE or AFTER Outlook was installed? If it was working after Outlook was installed, then something changed and you need to find out what so it can be corrected. If it hasn't worked since Outlook was installled, you need to work with your Outlook administrator to figure out why the emails sent from the mainframe are exhibiting that behavior.
As someone who uses Outlook on the PC and receives MANY mainframe emails every week (with subjects and bodies), I can assure you that the issue is AT YOUR SITE and something specific to your site is set up incorrectly. Hence you will need to work with people at your site to fix the problem. We on this forum do not work at your site and do not have access to the information to fix the issue.