nanog mailing list archives
Re: Blocking MX query
From: Ibrahim <ibrahim1 () gmail com>
Date: Tue, 4 Sep 2012 17:24:47 +0700
Hi Suresh, We create special NAT that all destination use TCP port 25 will be NATed to one public IP address only. And this public IP address is registered on most of RBLs. But we are still receiving complaint about spammer from this public IP address :-) Regards Ibrahim On Tue, Sep 4, 2012 at 5:12 PM, Suresh Ramasubramanian <ops.lists () gmail com>wrote:
Feel free to block port 25. Most if not all mail providers offer email access on webmail and on an alternate smtp port (587) If you have NAT - the problem is that if you have spammers abusing your service (or abusing other services on port 25) providers will end up blocking your NAT gateway IP and then you have a problem. You will want to look at walled gardens or similar to block spamming / infected users. Please see the maawg best practice for walled gardens and port 25 management. On Tue, Sep 4, 2012 at 3:37 PM, Ibrahim <ibrahim1 () gmail com> wrote:Hi All, I've read old archive about blocking SMTP port (TCP port 25). In mycurrentsituation we are mobile operator and use NAT for our subscribers and we have few spammers, a bit difficult to track it because mostly our subscribers are prepaid services. If we block TCP port 25, there might be "good" subscribers will not be able to send email. We are thinking to block MX queries on our DNS server, so only spammerthatuse their own SMTP server will got affected. All DNS queries from our subscribers already redirected to our DNS cache servers. But seem Bind don't have feature to block MX query. Any best practice to block MXquery?Regards Ibrahim-- Suresh Ramasubramanian (ops.lists () gmail com)
Current thread:
- Blocking MX query Ibrahim (Sep 04)
- Re: Blocking MX query Suresh Ramasubramanian (Sep 04)
- Re: Blocking MX query Ibrahim (Sep 04)
- Re: Blocking MX query Suresh Ramasubramanian (Sep 04)
- Re: Blocking MX query Ibrahim (Sep 04)
- Re: Blocking MX query Bacon Zombie (Sep 04)
- Re: Blocking MX query Ibrahim (Sep 04)
- Re: Blocking MX query Suresh Ramasubramanian (Sep 04)
- Re: Blocking MX query Ibrahim (Sep 04)
- Re: Blocking MX query Tony Finch (Sep 04)
- Re: Blocking MX query William Herrin (Sep 04)
- Re: Blocking MX query Rich Kulawiec (Sep 04)
- Re: Blocking MX query Jimmy Hess (Sep 04)
- Re: Blocking MX query Mark Andrews (Sep 04)
- Re: Blocking MX query Suresh Ramasubramanian (Sep 04)
- Re: Blocking MX query Rich Kulawiec (Sep 04)
- Re: Blocking MX query Suresh Ramasubramanian (Sep 04)