Most promotional email recipients (65%) engage with email in the afternoons and evenings, yet marketers tend to send emails first thing in the morning, according to a recent report by Retention Science.

The analysis of 100 million online transactions found that 38% of email conversions (emails that are opened, clicked through, and converted) occur in the afternoons and 27% in the evenings. Only 28.5% occur in the mornings, although that's the most popular time for promotional emails to arrive in inboxes.

Below, additional key findings from the report.

Days of the Week

• Tuesdays and Fridays had the most email conversions—28% of all conversions examined occurred on Tuesdays and 26% on Fridays.
• Saturday was the lowest-performing day of the week, with just 3% of conversions, followed by Sunday with 6%.

Promotional Offers

• The analysis also found that free shipping offers in promotional emails trumped percent off offers in terms of conversion.
• Free shipping offers converted at rates between 0.22% and 1.9%, making them twice as effective as price-reduction offers, which converted at rates between 0.1% and 0.8%.

About the research: The report was based on an analysis of 100 million online transactions, 20 million user profiles, and 100 email campaigns.