Thumbs up for the feature, I've tested it now a few days and I really like it in fact except for one little thing.
Yes it had been spoken, but it is the "from" feature.
In our case we have a mailbox where all emails from vbr and veb and even other backup solutions are coming from.
We have a script that puts the mail in the folder for the customer and our monitoring is scanning those for the status of the backup.
So this is why I for myself would like to have this option because the script is going through "where does it come from" "what says the subject" "alright, move to this folder".
Simple said. For now we are taking the script I wrote, there is the from and to option included and it works great. We do integrate veb to vbr in this case there is no need for that option but some customers do not have vbr not even esx or hyper-v and we made really positive results with veb.
So yes I would have it as a feature request and hey, when I can achieve it with a script, I think you can do this easily, too