Hi Ram, We are using ZXTM (also known as Stingray), with the built in SMTP options from the load balancer (which really isn't much..), everything im seeing in the config indicates it should be running and processing on the application layer, were there any settings on the F5 you had to adjust to indicate it was smtp traffic or was it just tcp by default?
Brad Riemann Techpro, Inc From: owner-postfix-us...@postfix.org [mailto:owner-postfix-us...@postfix.org] On Behalf Of Ram Sent: Friday, January 09, 2015 7:34 AM To: postfix-users@postfix.org Subject: Re: Issues using Postfix behind a load balancer On 01/07/2015 10:40 PM, Brad Riemann wrote: Hello! First time caller, long time listener :). I've been working on a new mail filtering solution for our company that revolves around the solution receiving inbound mail through a load balancer. We have come upon an issue that I am not finding any sort of documentation or notes that others have experienced.. We are using a load balancer behind a nat, that distributes the inbound emails to a clustered mail scanning solution (we have been having issues with our current solution where the existing servers are overloaded, and this gives us the ability to plug and play new servers with zero dns adjustments..) Now, our load balancers hands off the message to the first available postfix server, we get headers that look like the following (after postfix picks it up). -- Received: from batch.email.flyfrontier.com (edge1.dc1.domain.com [172.16.4.#]) by mta02.dc1.domain.com (Postfix) with ESMTP id ########### for <u...@domain.com><mailto:u...@domain.com>; Wed, 7 Jan 2015 10:48:52 -0600 (CST) -- The issue, if you don't see it, is that postfix seems to be using the load balancer ip as the last hop, and because the load balancer is just pushing content through it is not recording the previous hop to the headers, which is causing some issues.. This seems to be a Firewall NAT issue. The Load balancer would add a HOP if it is on the application layer. What is the load balancer you are using. We use LVS and we always get the IP of the smtp client machine on postfix, not the load balancer IP Thanks Ram
