Summary:

Mail Merge was not working in CRM but the Interactive Dashboards were working as expected.

Symptoms:

When trying to perfom a Mail Merge it was failing even though other Tomcat features were working as expected, ie: the Interactive Dashboard. 

Cause:

The cause of this issue was that a line in the crm.rewriter.rules file (C:\Program Files (x86)\Sage\CRM\Services\IISUtils\CRMRewriter) was chnaged to :

RewriteRule ^/sdata/crmj/(.*)$ http://servername:10009/crmj/$1?%{QUERY_STRING}&originalHostCRMRedirector=mercedes[P]

Resolution:

To resolve this issue this line will need to be changed back to what it was originally:

RewriteRule ^/sdata/crmj/(.*)$ http://%{HTTP_HOST}:10009/crmj/$1?%{QUERY_STRING}&originalHostCRMRedirector=%{HTTP_HOST} [P]

Once this line has been updated perfom a IIS Reset and Mail Merge should work as expected.