We have seen an increasing traffic on our main mail server this week so we started checking some accounts and we found a HUGE amount of undelivered bounce emails to accounts that we don't know.
Someone is spamming with emails from our domain, i know, but how do we fix this? We are getting around 100 undelivered emails every 5 minutes.
Is there a way to decrease this?
I don't know if zimbra supports this, we use sophos puremessage as an e-mail gateway, but what you want to do is create a SPF record for your domain and silently drop any e-mails that fail the spf check.
nice! seems to be working! Thanks!!
No, same thing. Thanks though