The holiday season in 2019 saw significant growth in email volumes, with over 4.2 billion emails sent on Black Friday and over 4.3 billion emails sent on Cyber Monday. Mobile devices accounted for a substantial portion of email opens during this period, with 65% of click activity happening on mobile devices. The analysis also revealed that mentioning the holiday in subject lines had a neutral effect on engagement, while using urgency or reminders about the date did not increase open rates. The optimal subject line length was found to be around 34 characters. Discounts were shown to have an inverse relationship with engagement rates, and relying solely on discounts may not deliver the desired engagement lift. Exclamation points and emojis in subject lines also failed to increase open rates. Ultimately, senders should focus on delivering value, understanding what their brand means to recipients, and differentiating their subject lines from competitors. Personalization is key, but achieving it through data-driven testing and segmentation is essential.