A useful default is to have your email arrive between 7:30 and 9:00 a.m. in the recipient’s local time zone. Bankers often check messages before the workday fills with meetings, calls, and live deal requests. Your note may get more attention then than it would during a busy afternoon.
Tuesday through Thursday mornings are generally sensible choices. Monday inboxes can be crowded after the weekend, while Friday schedules may be less predictable. There is room to disagree about the best weekday. Workloads vary by banker, group, office, and deal cycle.