Spellspam. Worldweavers, #2

"You've Got Mail" In a richly magical world, computers were the only things that were thought to be impervious to magic... or so everyone believed. Until ordinary emails that began by sounding like practical jokes started turning into real working spells, with increasingly perilous consequences. Thea Winthrop, double seventh, child of magic, had thought that her unique ability to access magic through this unexpected medium was something that was hers alone - until she discovers taht there is someone else out there - someone with similar powers, but bent on using them witha  wild and dangerous agenda.
And Thea, still finding her way through her new magical gifts, is called upon to step up and face a difficult decision, and a task that might break her.