Will i lose mail when i change my mx records, How long does it take to change my mx records – Google Message Security Troubleshooting Guide User Manual
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Frequently Asked Questions 35
Will I lose mail when I change my MX records?
No. While your MX record information is being propagated, your Inbox continues
to get mail delivery. Once the MX record update is completed, temporarily, your
Inbox has a mix of messages sent before the update and messages filtered by the
email security service.
For more MX record information, see the Activation Step-by-Step Guide’s chapter.
In addition, see the “How long does it take to change my MX records?” FAQ.
How long does it take to change my MX records?
It depends upon your domain host requirements. But usually the longest part of
this process is the propagation of your MX record changes throughout the
Internet. How long this takes depends on the current Time to Live setting (TTL).
This is typically measured in seconds, so a TTL of 3600, for example, means it
might take up to an hour for your MX record changes to propagate.
When editing your MX records, it is good practice to change your MX record’s TTL
field to 900 seconds (15 minutes). Remember this change takes the previous TTL
time period before the 15 minute TTL is in effect. But, once the 15 minute TTL
value is propagated, it is easy to make your MX record edits and run your system
tests. Once your MX record edits are validated, you can change your TTL field to
an optimal time period.
While your MX record information is being propagated, your Inbox continues to
get mail delivery. Once the MX record update is completed, your Inbox has a mix
of messages sent before the update and messages filtered by the email security
service.
For additional MX record information, see the Activation Step-by-Step Guide’s
FAQ.
About MX Record Propagation
Your DNS provider manages the master copy of your MX records. When
someone sends you mail, the Internet locates your address on your DNS server.
In this process, the sending mail server keeps a copy of your email address just in
case it needs to send you another message. Specifically, your MX record
information is cached on the sending server so that your DNS server is not
overwhelmed with Internet requests.
How long does a sending mail server keep a copy of your address? As long as the
copied MX record’s Time to LIve field (TTL) is current, the sending mail server
continues to send messages to your address. When this server has new mail for
you and your TTL has expired, the sending mail server goes back to your DNS
server for updated MX record information. This means that it will take your
updated MX record a full TTL time period to propagate changes to all of the
various mail servers sending you messages.