Hello, new to Zimbra, and the support forums. please forgive any newbie
My company is considering implementing Zimbra for their e-mail and calendaring solution. We are using the community version
Release 7.1.1_GA_3196.UBUNTU10_64 UBUNTU10_64 FOSS edition
mydomain.com gets a fair amount of NDR spam. in the past, before I was aware of such a problem, our domain did get on a RBL. Since that time, I set up a "catch-all" account, and manually go in and delete everything about once a month (around 1K spam e-mails / mo. )
I've searched for the term "catch all" here, and a few people have commented about the "spam ramifications" (or similar)
I would like to know what would be the best way to implement zimbra, in a situation where the domain does get targeted by NDR spam?
I am a bit new to all of this, so perhaps a detailed explanation if you would please?
thank you very much
Details of our current NDR situation, and how it (seems) to be dealt with
(please let me know if I'm mistaken, or am doing it wrong)
spammers create non-existant email address for our domain in to: field
they place target e-mail address in from: field
mail gets delivered to mydomain.com, e-mail server cannot deliver to
email@example.com, gets "bounced" back to firstname.lastname@example.org
mail is shown to be delivered from mydomain.com (either mailer-daemon, or some other address leading back to mydomain.com)
user (or some metrics) see this as spam, gets reported - domain is listed in an RBL.
So, to prevent the "bounces", I set up a catch-all e-mail address
i.e. email@example.com, and make it a valid account.
spammers send to firstname.lastname@example.org and then the mail server determines it doesn't belong to any active user, and then delivers to
email@example.com, and the bounce doesn't happen.
mail in firstname.lastname@example.org's account gets purged on a regular basis