We process over 6 million emails in and out on a daily basis.
additional info for those interested or who have problem. Backscatter has picked up big time this week for some reason.
Computer Security Research - McAfee Avert Labs Blog
I'm kinda new to the computer industry. Since 1976.
are you saying that Astaro wouldn't wouldn't know how to route a bounce if it's not configured to relay from the host to which it delivers email for a domain? I hadn't thought of that. Are you sure?
Bob, if you look at exim.conf, basically what astaro does is drop the message if you have any kind of verification turned on therefore all the messages are dropped at connection time if you have AD verification or verification with callout turned on. So no backscatter there.
By the way what are you doing moderating on a Friday night at 11:45 pm
It is odd to revive a discussion from 10 years ago, but the question still seems to be unanswered.
Does anyone know how to disable NDR messages from UTM?
Like the original post, I am aware that NDRs can become backscatter SPAM, or facilitate directory harvesting. Is it possible that Sophos thinks this is unimportant?
Official answer from support: Not possible.
(Although they pointed out that I can block incoming backscatter by enabling BATV, which I already use)
Has anyone tried disabling recipient verification? I wonder if it changes how bounces are handled, or if it just delays when the bounces occur.
Disabling recipient verification makes the mail server receive emails for non-existent accounts. I know that Exchange can handle them in different ways including bouncing them, but that would seem to be inefficient. It also can send an NDR or deliver such mail to a trashcan account. Others here know more about that than I.
Cheers - Bob