According to Forbes, "sending too many emails means employees will ignore some of your messages. If you’re continually emailing FYIs, most messages turn into a steady stream of static."
This is corroborated by another publication by Enplug which advises that organizations should consider sending out internal newsletters less frequently, rather focus on sending the "right information to the right people at the right time".
A 2015 report by Radicati Group found that an employee receives an average of 88 business emails per day with the number predicted to rise to 96 emails per day in 2019.
A publication by Papirfly noted that company-wide emails have a read-rate of about 37%.
Summary of Findings
The initial hour of research didn't find hard data from surveys or expert advice on the optimal number of internal emails that a large organization should send to maximize open rates. However, we found a suggestion of about 2 emails per day as a reasonable limit with no specificity on the size of the organization.
We propose further hours of research to dig deep for any available information that we could gather that could corroborate what has been found during the initial hour of research.
Only the project owner can select the next research path.