Episode 129 of "Sabrina, the teenage witch"
s06e10 Deliver Us from E-mail

Sabrina is a candidate for a writer's position at the local newspaper but her in-box is filled with annoying e-mails from her evil Other Realm twin. She responds by asking for the junk mail to stop, but her correspondent gets angry and sends Sabrina an e-mail virus that turns her into an airhead causing Mike & Josh to doubt her intelligence. Sabrina keeps getting e-mails from the Other Realm containing dumb limmericks about witches. She writes back to the unknown sender with a nasty note asking for the e-mails to stop. At the paper Sabrina tells Josh that she's got all of these great ideas for Mike about writing a column. Josh warns her that Mike never lets interns write columns but wishes her luck anyway. When Sabrina pitches Mike her ideas he knocks each one down saying that he's read these stories before. But, Mike encourages her to keep trying because she's on the right track. Little does Sabrina know, but the dumb e-mails are from her jailed evil twin Katrina. The nasty witch gets mad when Sabrina rebuffs her prose so she decides to get even by e-mailing back a virus that will turn Sabrina into an idiot. Josh notices something wrong with Sabrina when she sits in on a meeting with Mike and his staff. She spouts off the dumbest ideas for a column, ruining her chances for gaining any respect or her coveted column.Sabrina spends the day shopping, and acting more like Morgan than is healthy for her. Harvey sends Morgan off on a shopping errand and questions Sabrina about what's going on. He figures out that something magical is affecting her so he takes her to the Spellman house. The aunts realize that she's under a stupid spell and put two and two together about the emails. Only one person in the Other Realm would do that to Sabrina: Katrina. Aunt Zelda pays a visit to Katrina's cell, which she happens to share with Zelda's evil twin Jezebelda. Katrina won't tell Zelda how to cure Sabrina so Zelda bribes Jezebelda with Mary Kay cosmetics to find out the answer. All they have to do is fill Sabrina's head with as much knowledge as possible and hope she can display some common sense before daybreak.Let the classes begin. Harvey, Aunt Hilda and Aunt Zelda spend the entire night teaching Sabrina everything they can think of until she begins putting all the answers together herself. She's cured! Sabrina goes to the paper and explains to Mike and his staff that her behavior the day before was out of the ordinary and begins pitching intelligent ideas for a column. She then apologizes to Josh. And, she gets a little revenge on Katrina by sending her a "kill 'em with kindness" virus. Katrina ends up waiting hand and foot on roommate Jezebelda.