Example situation
You send the same Gratavid in bulk to 100 Walmart employees.
Result
Walmart flags your emails as spam, moves them to the junk folder, and doesn't deliver half of your emails.
Why does this happen?
Walmart employees are constantly sent emails from malicious users trying to phish their data. Malicious users send bulk emails to every Walmart employee to increase their odds of "successfully" tricking one employee. In order to prevent this type of spam, the Walmart IT team adds a spam filter that blocks senders from sending emails in bulk to employees. Unfortunately, these filters apply to Gratavid too.
Remedies
Before sending Gratavid's in bulk to the same organization ( i.e., emails ending in "@walmart.com"), it's highly recommended you implement a "warm-up" period by sending personalized videos ("Thank you, John Smith") to Walmart employees one at a time. As more and more Walmart employees engage with your personalized Gratavids, your Gratavid reputation will improve with Walmart.
Note: You might have to email these Walmart employees separately asking if they received your video and to check their junk folder. As Walmart employees engage with your Gratavids, remove them from junk, and respond your Gratavid reputation improves.
As your reputation improves, Walmart will start to trust emails from your Gratavid account, and you can begin sending Gratavids in bulk.