Email insurers (ESPs) often say they're untouchable in relation to sending bulk emails. However we need to understand that sending emails is generally totally free is actually some knowhow sending bulk emails reliably with good deliverability can be carried out totally free. So before we yield on the ESPs and pay their grotesque fees, try get moving on it yourself.
Ubuntu Server and Postfix earn a very reliable, lightweight and versatile combination for sending bulk email so when configured correctly he or she can easily match an ESP's service. Even on your domestic 8MB ADSL connection it is possible to send thousands of emails each hour. My concentrate on this post is show you the right way to implement it with minimal cost. I will not get into the precise clicks and commands (it isn't a dummies guide) even so it has to be decent snapshot of my effective model.
Firstly, you'll need an ISP that's in a position to deliver several static IPs. BeThere offer 16 static IPs for about? 2 on a monthly basis such as ADSL connection. You become 1 WAN IP and 15 alias IPs. You may also do you need a reliable router able to handle several DMZs - I can recommend the Draytek Vigor 2820.
Principally the architecture comprises a reasonably powerful server that offers a dedicated virtual machine (VM) host using VMWare ESXi server. Your machine hosts 11 Ubuntu Servers (10 dedicated Postfix emailing servers, 1 dedicated DNS server) each only needing the minimum RAM (256MB) and minimum harddisk space (8GB). Every virtual machine has an area static IP (e. g. 192. 168. 1. 10 - 192. 168. 1. 21) each Postfix server placed individually in a DMZ. It feels right 10 dedicated mailing servers, each sending originating from a dedicated external IP (e. g. 84. 252. 220. 200 - 84. 252. 220. 210). Configure your company's domain to possess a corresponding subdomain per each IP (e. g. email1. domain. com along with An all-time to 84. 252. 220. 200, email2. domain. com comes with an A list to 84. 252. 220. 201 etc). Ask your ISP's DNS team to configure the needed corresponding reverse IP (84. 252. 220. 200 to email1. domain. com etc). Create an SPF record aided by the openspf project website and use it for a domain's DNS server (you might want to ask your domain's service provider when they can execute this ).
Download ESXi server from VMWare's website and signup to discover the licence key. It's actually a very easy to use install (assuming your machine works iwth ). Next, install an Ubuntu VM with default settings (naming it e. g. email1. domain. com) and install Postfix (again default settings). Configure a static IP, DomainKeysDKIM and export individuals answer to your domain's DNS server. Use telnet in the linux terminal to ensure you're able to send emails that can be DomainKeys/DKIM signed and SPF authenticated. Getting almost all these to work together correctly might be a tiny nightmare therefore the Ubuntu community guides are priceless. Once all set to test, Google Mail is definitely a good choice for viewing an email's full source and will allow you to verify the IP it originated (e. g. 84. 252. 220. 200), its corresponding website name (email1. domain. com), whether or not the DomainKeys/DKIM signature passed and whether your SPF record is setup correctly.
SPF, DKIM and DomainKeys passing Gmail
Congratulations! You can have an avid Ubuntu Postfix mailing server. Now, come up with a second Ubuntu server virtual machine and install BIND, this can be the dedicated DNS server (named e. g. emaildns). Configure the forward lookup to whatever you fancy (Make the most of OpenDNS) and test its abilities using nslookup. Reconfigure your dedicated emailing server's (email1 or everything you could referred to it as ) default DNS server to emaildns. We would like the whole Ubuntu Postfix mailing servers querying here so our network isn't delayed over time and bandwidth consuming DNS lookups.
Once you're happy everything's being employed as it needs to you can shutdown email1 and copy the files 9 times to clone the VM or manually do the installation 9 more times. Cloning VMs is able to bring up issues like duplicate NICs and then in my experience when you've setup 1 email server different ones make a fraction of that time period. Ensure all have a similar DomainKeys/DKIM private key!
When you're finished you will be getting 10 dedicated Ubuntu Postfix servers eager to deliver your mail from 10 separate external IPs. Whatever software you have to bring about and send your emails should handle 10 SMTP servers; Campaign Enterprise certainly can that has a tiny amount of configuration.
The Final Result
Now you might have ten dedicated Ubuntu Postfix email servers, all really small, lightweight installations that demand little or no CPU load utilizing their own external IPs (and hostnames) setup to question a similar DNS server.
The best benefit? I achieve industry degrees of deliverability making use of this model to provide a source exception of one's server and ADSL contract it's free! I've even recently was built with a call from Return Path asking whether I desired any help. After discussing my stats they concluded they couldn't help! Awesome.
Now, to very much optimize your server's mailing performance, see my post on Performance Tuning Postfix for sending bulk email.
