When an email needs to be sent to a small number of people, or one person (for example, if a constituent was missed off a large mailing), there is no quick way to input the email address/constituent ID which the email should be sent to. Even for one address a new list has to be created, from a query and saved, which is time consuming.
For small numbers of email addresses (eg. 1 - 10) it would be really helpful to be able to directly copy the email addresses/constituent IDs which the email should be sent to without building a list.