You say this:
I have a client who gets spam emails addressed as her email address.
And then say this.
How do I deal with this junk? I changed her password to a more robust
one but that didn’t stop the spam from coming in still.
The SPAM is forged as being from her address and it’s painfully simple for anyone in the world to pretend the
from address in an e-mail is something that it is not. So changing her password won’t stop this issue. In fact if somehow hackers got her e-mail address, the least they would do is use it to send SPAM to her; but that is a whole other discussion.
That said the best thing she can do as a user is to apply some kind of junk mail filtering to her mailbox. You don’t state what OS she’s on or what e-mail clients she is using, but Gmail, Yahoo and even Mac OS X mail have built in junk filtering capabilities.
Now if the concern is whether SPAMmers will e-mail others pretending to be her? You can’t control that. The most basic SPAM filters in the world should be able to detect that level of forgery and anyone nowadays using e-mail should have SPAM filtering of some kind in place.