How To Disable Bounces And Sender Verify With Exim?
Oct 11, 2007
in the last few months Ive got a blacklist warning from spamcop over my server sending bounces and now I find out one of my ips is listed at [url]for doing sender verify and bounces.
I think both of which are ridiculous to blacklist for and I really think most of the anti-spam blacklist people are nothing more then money making rackets. But I guess it seems reasonable to disable these things as it would save some resources.
Anyway what I need to do I guess is only do bounces for local users and disable sender verify. What is the best way to do this with exim?
Every server I have to change is cpanel. Ive googled on this the last 2 days and cant find much info, Mailservers isnt my strong point for sure. Any advice Id appreciate.
UPDATE I found how to disable callouts [url]
Just trying to figure out how to disable bounces now
We had a non-client (not on our server) that was getting 550 email rejections when he attempted to email us due to having Sender Verify enabled.
In the past I figured Sender Verify was necessary for fighting spam, amongst other things, but have realized that we may be having more rejections than we know because we never hear about them.
Is there a general best practice in terms of enabling Sender Verify or leaving it off? I've never heard about complaints about rejects from legitimate emails senders, so it doesn't seem to be an issue, but then again, you really never know...
I have this customer who have been having trouble to receive some emails from valid senders due to Sender verify failed, both senders have valid accounts.
Here is an example,
De: MDaemon at zeus.XServer.com [mailto:MDaemon@zeus.XServer.com] Enviado el: sábado, 17 de noviembre de 2007 11:16 a.m. Para: albertocarbone@XServer.com Asunto: Error permanente de entrega
Failed address: jsoler@CustomerDomain.com
--- Session Transcript --- Sat 2007-11-17 11:15:19: Parsing message [xxxxxxxxxxxxxxxxxxxxxxxxpd35000148823.msg] Sat 2007-11-17 11:15:19: * From: albertocarbone@XServer.com Sat 2007-11-17 11:15:19: * To: jsoler@CustomerDomain.com Sat 2007-11-17 11:15:19: * Subject: RE: Zona Franca.- Concepto.- Sat 2007-11-17 11:15:19: * Message-ID: [003201c82934$ba953d00$2fbfb700$@com] Sat 2007-11-17 11:15:19: Intentando SMTP conexión con [CustomerDomain.com] Sat 2007-11-17 11:15:19: Resolviendo registros MX para [ CustomerDomain.com] (Servidor DNS: 200.118.2.66)... Sat 2007-11-17 11:15:23: * P=000 S=000 D=CustomerDomain.com TTL=(240) MX=[ CustomerDomain.com] {xx.xxx.13.172} Sat 2007-11-17 11:15:23: Intentando SMTP conexión con [xx.xxx.13.172:25] Sat 2007-11-17 11:15:23: Esperando la conexión del socket... Sat 2007-11-17 11:15:23: * Conexión establecida (xx.yyy.51.30:3948 -] xx.xxx.13.172:25) Sat 2007-11-17 11:15:23: Esperando la iniciación del protocolo... Sat 2007-11-17 11:15:25: [-- 220-svr01.customerDomainHost.com ESMTP Exim 4.68 #1 Sat, 17 Nov 2007 11:15:29 -0500 Sat 2007-11-17 11:15:25: [-- 220-We do not authorize the use of this system to transport unsolicited, Sat 2007-11-17 11:15:25: [-- 220 and/or bulk e-mail. Sat 2007-11-17 11:15:25: --] EHLO zeus.XServer.com Sat 2007-11-17 11:15:25: [-- 250-svr01.customerDomainHost.com Hello zeus.XServer.com [xx.yyy.51.30] Sat 2007-11-17 11:15:25: [-- 250-SIZE 52428800 Sat 2007-11-17 11:15:25: [-- 250-PIPELINING Sat 2007-11-17 11:15:25: [-- 250-AUTH PLAIN LOGIN Sat 2007-11-17 11:15:25: [-- 250-STARTTLS Sat 2007-11-17 11:15:25: [-- 250 HELP Sat 2007-11-17 11:15:25: --] STARTTLS Sat 2007-11-17 11:15:26: [-- 220 TLS go ahead Sat 2007-11-17 11:15:26: SSL negotiation successful (TLS 1.0, 1024 bit key exchange, 128 bit RC4 encryption) Sat 2007-11-17 11:15:26: --] EHLO zeus.XServer.com Sat 2007-11-17 11:15:26: [-- 250-svr01.customerDomainHost.com Hello zeus.XServer.com [xx.yyy.51.30] Sat 2007-11-17 11:15:26: [-- 250-SIZE 52428800 Sat 2007-11-17 11:15:26: [-- 250-PIPELINING Sat 2007-11-17 11:15:26: [-- 250-AUTH PLAIN LOGIN Sat 2007-11-17 11:15:26: [-- 250 HELP Sat 2007-11-17 11:15:26: --] MAIL From:[ albertocarbone@XServer.com [mailto:albertocarbone@XServer.com] ] SIZE=23231 Sat 2007-11-17 11:15:26: [-- 250 OK Sat 2007-11-17 11:15:26: --] RCPT To:[jsoler@CustomerDomain.com] Sat 2007-11-17 11:15:30: [-- 550-Verification failed for [albertocarbone@XServer.com] Sat 2007-11-17 11:15:30: [-- 550-Called: 82.165.181.92 Sat 2007-11-17 11:15:30: [-- 550-Sent: RCPT TO:[albertocarbone@XServer.com] Sat 2007-11-17 11:15:30: [-- 550-Response: 550 Backscatter Protection detected an invalid or expired email address Sat 2007-11-17 11:15:30: [-- 550 Sender verify failed Sat 2007-11-17 11:15:30: --] QUIT --- End Transcript ---
!verify = helo !verify = reverse_host_lookup in exim acl and drop message if helo is not passed. But one issue is this validates for users even having account in the server and trying to send mail using server account to someone else
I want to put validation for only incoming mails "to" this server
What i dont want is to validate the mails that authenticated smtp users send
My mail server receives tons of messages directed towards bogus, non-existant addresses at my domain. When those addresses don't exist, it creates a reply email with the subject "Mail delivery failed: returning message to sender". How do I stop exim from doing this?
So I get this email today from SpamCop complaining about my server sending unsolicited bounce messages.
Well yea... thanks to spammers domain spoofing and sending spam to my server, my server finds that there's no address - so it replies to the spoofed address.
My question is.... what do I do about it? The spamcop site has this to say... Though if I setup the server to do something odd like not sending a bounce because it's "filed internally", how will legit people get the proper bounce response??
Problem: Misdirected bounces
Description: When a mail server accepts a message and later decides that it can't deliver the message, it is required to send back a bounce email to the sender of the original message. These bounce emails are often misdirected.
Solution: Upgrade and/or configure your mail server software so that this situation is never encountered. Configure your software to either reject messages during delivery or accept them permanently. Do not let your software make choices about delivery after it has accepted a message. If you must accept delivery before you know the status of a message, then file it internally - do not send, forward or bounce it outside your organization. The errant message can be placed in a special folder or routed to your postmaster.
I had a server admin install a new drive in RAID 1 (mirrored drives). I'm not the best linux guy in the world... but is there a way either through linux, WHM/cPanel, etc. to check and verify that the drives are mirroring correctly? I just want to sleep soundly everynight knowing if a drive failed I'd have another drive up and going.
if there was a way of remotely verifying my dedicated server architecture.
The hosting is done through our design company who then use a 3rd party for hosting a number of sites, and as such I don't have direct access to server control panels etc.
Short of just taking their word for the fact that we have the servers we're supposed to, I was wondering if there's any way I can be sure. We're supposed to have dual web servers plus a database server.
in the last couple of days we really have problem accessing web service, while ftp, ssh, work fine. While we getting connection time out, the load on the server is really load around .2 and get numerous e-mail from Cpanel that httpd is failling and try to restart.
How can i do to check and verify that there a DDOS attack?
What step can i do to possibly minimize DDOS attack?
