Currently once you request for a batch of emails to be validated from the EDM/Report Writer section, there is no tracking so you can see the progress of this. Especially when validating a large number of emails (10k plus) this can take up to 4 hours and RMS obviously times out in that time frame.
Once you log back in you cannot see where the validation progress is up to until you get a completion email.
There was two times last week where the validation process must have crashed and never received a notification that it failed and needed to be processed again.
On one of these occasions I was processing 20k emails and had to wait another 7 hours for it to process and could not get the promotional EDM out when I had planned to.
I have been tracking the time frames on all of these validations if you require more information.