This inundation of email has continued into the holidays, including a 68 percent increase in messages from travel companies, and a 36.4 percent increase from retailers, according to Experian. However, only retailers have been able to match last year's transaction rates.
Experian attributed that trend to retailers' ability to "better segment and target messages" so they're relevant to individual shoppers. That said, the number of emails that can be directly linked to a transaction remains minuscule at 0.05 percent.
Experian's findings aren't the first sign that retailers are making strides in using data to better connect with consumers. Last month, data from Adobe's Digital Index found an increase in traffic from email marketing was contributing to the rise in online sales.
"People have gotten very used to receiving those promotional emails in the very early hours," Adobe's Tamara Gaffney said.