A God way to Change MX Records

Email is critical to a business, and it’s continued flow is paramount.

When changing MX records (for example a company aquisition or the purchase of an email filtering solution) you should always be careful not to break anything.  A lot of systems use MX records as a way to check spam mail, and if they don’t work you may have problems sending and receiving emails.

A way we discovered to make sure you don’t break email goes along the following which although takes eight calendar days in which to implement fully, it is a belt and braces approach and is definitely safe.

Assume you’ve just bought a hosted email security service and they have given you the servers mx1.emailprovider.com and mx2.emailprovider.com to change your own records to.

Day 1 MX Records

mx1.companya.com = 111.222.333.111

mx2.companya.com = 111.222.333.112

MX preference = 10, mail exhanger = mx1

MX preference = 10, mail exchanger = mx2

Day Two MX Records

mx1.companya.com = 111.222.111.111

mx2.companya.com = 111.222.111.112

mx1.emailprovider.com = 222.111.111.111

mx2.emailprovider.com = 222.111.111.112

MX preference = 10, mail exhanger = mx1

MX preference = 10, mail exchanger = mx2

MX preference = 20, mail exchanger = mx1.emailprovider.com.

MX preference = 20, mail exchanger = mx2.emailprovider.com.

Day Four (Yes Day Four) MX Records

mx1.companya.com = 111.222.111.111

mx2.companya.com = 111.222.111.112

mx1.emailprovider.com = 222.111.111.111

mx2.emailprovider.com = 222.111.111.112

MX preference = 10, mail exhanger = mx1

MX preference = 10, mail exchanger = mx2

MX preference = 10, mail exchanger = mx1.emailprovider.com.

MX preference = 10, mail exchanger = mx2.emailprovider.com.

Day Six (Day Six) MX Records

mx1.companya.com = 111.222.111.111

mx2.companya.com = 111.222.111.112

mx1.emailprovider.com = 222.111.111.111

mx2.emailprovider.com = 222.111.111.112

MX preference = 10, mail exchanger = mx1.emailprovider.com.

MX preference = 10, mail exchanger = mx2.emailprovider.com.

MX preference = 100, mail exhanger = mx1

MX preference = 100, mail exchanger = mx2

Day Eight MX Records

mx1.companya.com = 111.222.111.111

mx2.companya.com = 111.222.111.112

mx1.emailprovider.com = 222.111.111.111

mx2.emailprovider.com = 222.111.111.112

MX preference = 10, mail exchanger = mx1.emailprovider.com.

MX preference = 10, mail exchanger = mx2.emailprovider.com.

MX preference = 100, mail exhanger = mx1 Deleted

MX preference = 100, mail exchanger = mx2 Deleted

Don’t forget to update your firewall rules accordingly.