I was getting the same warning as the following rt-devel post which I found online - though I'm not subscribed to so I'm posting my fix here instead.
http://lists.bestpractical.com/pipermail/rt-devel/2015-July/012362.html [warning]: Warning: Use of "localtime" without parentheses is ambiguous at /opt/rt4/sbin/../lib/RT/Interface/Email.pm line 526. Correction is to edit Email.pm and where it has "localtime", use "localtime()" instead. Cursory search online for perl localtime shows examples with correct syntax. Note: Am working in RT 4.2.11 Thanks, Dominic
