How do you segment for send-time optimization?

Send time optimization segments subscribers based on when they are most likely to engage rather than sending everyone the same message at the same time. This approach uses historical engagement data to identify patterns such as a subscriber who consistently opens emails on Tuesday mornings or another who engages on weekends.

You can segment by timezone to ensure emails arrive during local business hours or morning routines. You can also segment by observed behavior, tracking when each subscriber typically opens emails and scheduling sends accordingly. Many ESPs offer send time optimization features that automate this process using machine learning.

The benefit is twofold. Subscribers are more likely to open emails that arrive when they are checking their inbox, and spreading sends across multiple time windows reduces the risk of overwhelming mailbox provider filters with sudden volume spikes. The challenge is maintaining enough send volume per window to sustain deliverability momentum. Send time optimization is like timing your arrival at the harbor to match the high tide.