I can offer only second-hand knowledge, but I was told at the time that Lotus was intending to keep the RAD aspects and drop email from it completely, leaving c

I can offer only second-hand knowledge, but I was told at the time that Lotus was intending to keep the RAD aspects and drop email from it completely, leaving cc:Mail as a standalone product. But IBM came along and wanted to modernize their email system, so Lotus took a deal to take the direction IBM wanted because it also brought massive marketing and consulting power and could drive adoption better than Lotus could.