Most of a working day passes between an inbox and a calendar, and the two rarely work together. Almanac puts them in one window with a calmer, simpler interface: your mail on one side and your day on the other.
Almanac also screens what reaches you. Messages that imitate a sender you trust, point to a link that isn't what it claims, or come from a domain made to look like your bank are held before they reach your inbox, with a plain explanation of why.