Shared IP email hosting questions

blaszlo

blaszlo

Verified User
Joined
Jun 9, 2008
Messages
116
Hey guys,

I have been reluctant to offer email hosting on my server, as it is setup for almost all clients to use the shared IP. The way it is setup now, every client that wants an email solution, I have been giving them their own IP. The reason being is because if they decide to use their email improperly and get blacklisted, it doesnt affect all of the clients on the shared IP. Here is my question...

I want to somehow offer an email solution to my clients on the shared IP's without having to worry about the entire IP being blacklisted if someone messes up. How would I start looking at this? Any advise is aprpeciated.
 
I think you have a misconception. Unless you have modified exim.conf all outgoing mail goes out on the main server ip regardless of what ip you have assigned the domain in the DA control panel. So you are already using a shared ip for outgoing email.
 
You are correct. All static clients send mail out using their own IP, the rest of the mail goes out through the main server IP, which is also the shared IP. How do I make sure if somebody abuses their email rights on teh shared IP, that it doesnt reflect on everyone else hosted on that IP?
 
All static clients send mail out using their own IP
Click to expand...

So you added the code to exim.conf:

Code: 
   interface = ${lookup{$sender_address_domain}lsearch{/etc/virtual/interfaces} {$value}{x.x.x.x}}

And created the file /etc/virtual/interfaces to put the domains and ip's.


How do I make sure if somebody abuses their email rights on the shared IP, that it doesn't reflect on everyone else hosted on that IP?
Click to expand...

You cannot.
 
So what do email hosts like Google, AOL, Yahoo, etc etc do when someone abuses their email for spam? Given, I know they have hundreds of server, but there are thousands of clients on each of their servers. If one of google's IP's gets blacklisted, thousands of people will be affected. Not trying to compare my little server to that such as google, but what do they do? I'm sure they don't let their shared IP's get blacklisted
 
You never responded to Floyd as to whether or not you made custom changes to exim.conf so that all your users with their own IP#s also use it for outgoing email, so none of us know if you're currently using owned IP#s for outgoing email or not.

Actually, Google, AOL, Yahoo, get into blocklists all the time. When they do, and they're notified, they (a) remove the offending account, and (b) get themselves unlisted.

The other theing they do is publish their outgoing IP#s in public whitelists so you can still get mail from them even if they're blacklisted, if you use the whitelist first. The new version of my SpamBlocker-powered exim.conf file will include the whitelist.

The problem of course is if you use it, you'll get more spam.

And of course if you get yourself whitelisted then you must be extremely proactive and very fast to remove accounts belonging to offending users, or you'll find yourself removed from the whitelist and not able to get back on (and possibly blacklisted as well, by at least some of the important blacklists).

Jeff
 
Sorry, I have misread his post - and no, I have not made any custom changes to exim.conf, but I will tonight for sure as it seems I was under a huge misconception. Also, I will consider the new SpamBlocker as well. So far I have not had a problem on this box, but I have been coming across huge problems lately with quite a few Exchange servers and I want to be proactive as opposed to reactive with this solution if possible. Thank you guys for all of your quick responses and feedback, you answered all of my questions - as usual.
 
Created the file /etc/virtual/interfaces and added...
bradlaszlo.com: 72.236.153.57

Added the code above with the shared IP of my server as the x.x.x.x variable into exim.conf just below the line "driver = smtp"

Restarted Exim, sent a test email and all worked as planned... Thank you guys!
 
Last edited:
Now make sure the spf record for bradlaszlo.com is 72.236.153.57
 
Done, thanks... Do I need to get in touch with my ISP to setup reverse DNS for this IP too?
 
Any ip that sends out email needs to have PTR records.
 
blaszlo said:
Created the file /etc/virtual/interfaces and added...
bradlaszlo.com: 72.236.153.57

Added the code above with the shared IP of my server as the x.x.x.x variable into exim.conf just below the line "driver = smtp"

Restarted Exim, sent a test email and all worked as planned... Thank you guys!
Click to expand...

What about domainkeys configuration ?
 
What about domainkeys configuration? Do you want to clarify your question a bit?
 
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