We use method 1 and have been for 15+ years. The *vast* majority of software out there follow MX's decently. Every once in a while when one of those edge systems is down we'll get reports that something inbound failed, but it's very few and far between.
We have 3 inbound receivers on the MX records and it's almost perfect on load balancing across them. Oh, we receive about 27 million inbound connections per month on the perimeter. From: Tu, Kevin [mailto:k...@ccscorporation.ca] Sent: Monday, February 28, 2011 10:30 AM To: MS-Exchange Admin Issues Subject: Load Balancing Incoming Email Using DNS MX Records Hello, It seems there are two ways to load balancing incoming email using DNS MX records. Method 1: Multiple MX records with equal priority. Method 2: One MX record with multiple IP address. What's the pros and cons? Somebody suggested the Method 1, because multiple MX entries with the same priority will cause the mail to be delivered faster to the alternative server if the first one it tries is unavailable. Is that right? Thanks, This email and any files transmitted with it are solely intended for the use of the addressee(s) and may contain information that is confidential and privileged. If you receive this email in error, please advise us by return email immediately. Please also disregard the contents of the email, delete it and destroy any copies immediately. CCS Corporation and its subsidiaries do not accept liability for the views expressed in the email or for the consequences of any malicious code that may be transmitted with this email. This email is also subject to copyright. No part of it should be reproduced, adapted or transmitted without the written consent of the copyright owner. CCS-06-01-2009 --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe exchangelist