I cannot find an email template another staff member saved.
Email templates are saved at the author's security log-in level. But this can be changed so that others can use the template too.
The email template was likely saved at a higher security level than the one you are logged into. Ask the other staff member who created/saved the template originally to go to Communicate > Email > Templates, and find the template you are looking for. In the far right column, they are able to click on the Security Level and adjust accordingly. This allows the creator to change the security level for that template.