Sending e-mail messages to more than one or all e-mail addresses

[Annette]

I have a table created for contacts. There is a hyperlink field. The e-mail
addresses are entered by users inputting "mailto:" prior to the address.
They then can click and open our default e-mail message. Not all records
have an e-mail address.

How can I create a function to allow them to select more than one contact to
e-mail? How can I create a function to allow them to select all the existing
e-mail addresses to e-mail?

Thanks in advance.