Thank you  @Craig_Thonis  for your contribution.We're on that. and we hope to find the reason.We have ruled out several of the options that you have mentioned, such as the weight of the deliveries (which could affect).

For a month now, we detected random delays in the delivery of the emails they are sending from the Adobe Campaign platform. we escalated the problem to our email administrators, after analyzing several emails, and the reason for the delay, They identified several servers adobe responsible for these ...