Migrating MX Records
Posted on 2012-08-27
I am deploying a new email gateway that will handle TLS and web based email delivery, really all email delivery to/from my company. Previously I was running exchange only. I am planning the migration and am trying to decide on the best way to handle DNS(MX) records. Currently mail is delivered to mail.domain.com, mail2.domain.com, and mail3.domain .com with pref.s of 10, 20, and 30 respectively. All point via different ISP's to the same mail server internally named mail.domain.com. My thought was to name the new mail proxy smail.domain.com (and get an SSL cert for said name). I could create public A & MX records with MX preferences of 15, 25, and 35 for smail, smail2, smail3. Thus until I took exchange out of line for direct email delivery, it would be attempted first. Once the gateway is up and tested, I could remove the mail.domain.com records from the MX list. I’m just running this by to be sure I’m not missing something obvious and disastrous. Would this work?