How does timing affect deliverability?

Timing influences deliverability in several interconnected ways:

Server load and throttling: Sending large volumes at peak times (top of the hour, business day start) can trigger ISP throttling as mail servers manage incoming traffic. Spreading sends reduces throttling risk.

Engagement patterns: Emails arriving when recipients are active get opened faster. Quick engagement signals relevance to mailbox providers, positively influencing inbox placement for future sends.

Competition for attention: Sending when inboxes are flooded (Tuesday 10am, for example) means competing with more messages. Your email may get buried before the recipient sees it.

Time zone considerations: A 9am send in your time zone arrives at 6am or midnight in other zones, affecting whether recipients engage or ignore.

Timing is not just about when recipients read email. It affects how mail servers process your messages and how quickly recipients respond, both of which shape your reputation.