Emailing Identities

Probably more related to webfaction actually, nonetheless - I have two email identities at the moment: 'admin@...' and 'lydia@...' but it's basically just admin. I can't send from lydia, though I can receive. Apparently it could/should be set up in a different way whereby I login in my own name, and then admin is linked to there. In this way, in the future if there's another administrator emails can be directed to them without unnecessary overlapping of personal emails. Not sure if this makes sense and how easy it would be to rearrange, but a thought where improvement would be welcome.