Account mail provides a Form API element to easily edit a user's email address.
Many sites which have registered users capture a number of profile fields about a user, such as name, job-title, email address, etc. Drupal typically handles this by having two tabs below user/123/edit
: Account and Profile. This can prompt a usability issue, where users go to one URL to change their personal details, but a different URL to change their email address.
Typically I get asked to add an "Email address" field to an arbitrary form, such as their profile form. This usually meant a fair amount of custom code: a form_alter to add the new field, some validation handlers, submit handlers, etc. This module tries to abstract this out by providing a reusable Form API element for editing the 'mail' field for Drupal users.