Legacy application unreachable code
Your assessment is correct, the emailList null checks are redundant in that block.

I would recommend that you use the "FindBugs" tool to perform static analysis on your code. It is available as a plugin to Eclipse, and other tools too. FindBugs would clearly indicate and mark all instances where these problems happen, and also a bunch of other things too.

Additionally, I would neaten things up by pulling just one final local variable for the response.getOutputStream() too. Additionally, you should be using generics, and enhanced-for (for-each) loops over your emailList.

Summarizing this would be:

...
else if ((emailList != null) &amp;&amp; (emailTest != null) 
              &amp;&amp; (emailTest.compareTo(IParameterNames.EMAIL_GO) == 0))               
         {

            PrintOutputStream respos = response.getOutputStream();
            respos.print("...blah blah blah...");
            respos.print("...blah blah blah...");
            respos.print("...blah blah blah...");

            respos.print(emailList.size());

            respos.print("...blah blah blah...");
            respos.print("...blah blah blah...");

            respos.print("...blah blah blah...");

            for (EmailMessage email : emailList) {
                if (email != null) {
                  respos.print(outputEmailAddressAsHTML(email, i).toString());
                }
            }

            respos.print("..lots.of.blah blah blah...");
          }