I agree with AST, just one quick email if you feel like you might regret it if you dont send one. However, I would word it a little better than what you wrote in your post..I dont think informaling is a word Good luck to you!
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"It's not a house, it's a h o m e."- ΑΟΠ ♥
Recruitment Advisor
Personal contact with a member would be way preferable to a cold email. Surely some of these girls are in your classes or involved in the same activities.
Agree with the last two posts. Also, don't believe everything you see on Facebook. While it may look like they are open to informal rush, creating such a page also may simply be a requirement they are filling with their HQ or the university. Kind of like a workplace who posts a job opening to fill EEOC guidelines when they know full well who they're going to hire.
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It is all 33girl's fault. ~DrPhil