Conventional wisdom says that business-to-business (B2B) sales emails are the most effective when sent during work hours, because that’s when customers check emails the most. Conventional wisdom also says that customers don’t like being interrupted when they’re not at work; therefore emails sent during off-hours are likely to create resentment.
Conventional wisdom is wrong. Emails that arrive during work hours–especially from sources with whom the customer isn’t immediately familiar–tend to get lost in the shuffle. By contrast, emails that arrive during off-hours are actually more likely to be opened, read, and (most important) get a response.
This is especially true during the holiday season. According to a study conducted in 2010 (back before everyone had a smartphone), 59 percent of Americans were checking their work emails over the holidays. That percentage is undoubtedly much higher today. So emailing over the holidays–even on the holiday itself–is actually a good strategy.
Read more here: https://www.inc.com/geoffrey-james/heres-how-to-do-an-effective-last-minute-email-campaign-for-holidays.html