We have tags to "forward to a friend", "unsubscribe" and "view web version" bu8t how about a tag that a recipient can use to change their email address easily. I've noticed some other service providers now have this feature.
There is actually a Preference Center link you can use - is that what you had in mind?
Perhaps. How would that let them change their email address - assuming that is all the data we have on them ie. no firstname lastname and no preferences?
The Preference Center gives the subscriber access to change any information you have for them. So if you only have their email address you can set it up so that they'd be given a form with just the email address field and access to change it.