Do you use Feedburner? They offer the email subscriptions & here's how to add the link to your sidebar:

I don't know how comfortable you are with html, but if you add an html widget in your sidebar, you can just copy the html code from feedburner & make the link say whatever you want.

For example, here's my html code from my feedburner (I went to "Publicize" then "Email Subscriptions" and I grabbed the code at the bottom under "Preview subscription Link")

<a href="http://feedburner.google.com/fb/a/mailverify?uri=IngenueMom&amp;loc=en_US">Subscribe to Ingenue Mom by Email</a>

The bolded part can be switched to say whatever you want & the link will say that.

A belated thanks for the reply - it's been a busy few days.  I don't use Feedburner but I will look around based on what you said here when I get a moment.