[Zope] Problem with Zwiki mail-out

I am using Plone 2.1 and Zope 2.8.4-final, python 2.3.5, Zwiki 0.46.0 I am not having any luck getting mail-out working. The subscribe button won't appear on my zwiki and I am out of ideas as to why. I've uninstalled and reinstalled zwiki, deleted and remade the mail_replyto property, deleted and remade the MailHost object...people can get their passwords emailed to them when they sign up so I know MailHost is configured properly. I have read HowToSetUpMailOut on zwiki.org and it seems so simple. I successfully set this up once on a clients Zwiki but no longer have access to that system to look for differences. Am I missing something here? Thanks in advance for any help that can be provided.