Slack created a new solution for workplace communication, one copied by many, even Microsoft . But the product, which is meant to help individuals and businesses collaborate, has been critiqued for sending too many notifications, with some claiming it’s sabotaged workplace productivity . Quill , a startup led by Ludwig Pettersson, Stripe’s former creative director and design aficionado, claims to offer “meaningful conversations, without disturbing your team.” The company has raised a $2 million seed round led by Sam Altman with participation from General Catalyst, followed by a $12.5 million Series A at a $62.5 million valuation led by Index Ventures partner and former Slack board observer Sarah Cannon, TechCrunch has learned. Quill and Cannon declined to comment. The company, based in San Francisco, has created a no-frills messaging product. Still in beta, Quill plans to encourage fewer, more focused conversations with a heavy emphasis on threads, sources tell TechCrunch . The pr...