All posts tagged mx

MX Records, FQDNs, Host Names and Dots

It seems that something as critical as email for the business environment should be protected at all costs, and that too goes for making any changes to said email servers.  Especially when the nature of email is that it can take up to 48 hours for any mistakes you make to a internet facing infrastructure to propagate themselves out.  So knowing what you are doing is vital.

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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.