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Hi there!

We are planning to switch our business to google workspace. I have seen some guys of you already accomplished this migration task so I am curious if somebody can help me out.

The idea was to set up dual delivery during the migration phase. So emails arrive in the mailbox abc@blah.de on our actual primary legacy server (external hoster) PLUS emails arrive in the mailbox abc@blah.de on the google workspace site. So no mail gets lost and we can smoothly transfer user by user. That is the idea!

Is this possible without having google as primary host…this would be the step AFTER we migrated everything?!

Thanks in advance…appreciate any hints on this or even better solutions! :slight_smile:

Cheers

Stevie

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Stevie,

While possible (I’ll get to that in a minute), dual delivery is not recommended as a best practice. A global Go-Live with the MX record cutover is the way to go. You can run a delta migration later and grab the last few items that make it your legacy system.

One of the biggest reasons to avoid dual delivery is internal routing. Google respects the public MX and will route to your legacy host. But, a mail client attached to your legacy server will send the message directly to your server - your server will see an internal address and will say “I’ve got a mailbox for stevie@company.com, let me put it here.” The message won’t make it out to the Google inbox unless you establish routing on the legacy system to do so.

Reasons to go through the pains of Dual Delivery:

  • companies with more many hundreds or thousands of users
  • multiple domains
  • geographic based go lives

If you do have to go Dual Delivery, you have to decide which system is going to be the holder of the MX records. Typically Google has better tools/ flexibility for managing the routing. Google for the public MX and then Google routes inbound over to the legacy system based on Organization Units or Groups of users that your keeping in the legacy system.

In short, don’t do it. Happy to have a convo on this if you want a hand.

1 Spice up
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Hi Tony!

Thank you for your time…that quick reply and your thoughts on this!

I contacted our hoster and they replied that dual delivery is not supported on their end…we have to do the cutover anyway.

So the scenario you suggest is doing the hard cut after business hours…probably weekends (considering around 24 employees and 20 shared mailboxes)…

While I touch and change MX records on our hosters site can I be sure that no mails get bounced (if at all) or that nothing gets lost within this ~24-72 hours assuming that i added all mail groups & users to google workspace beforehand?!

Do you have any best practice advice eventually how to plan this? Sorry for bothering but this is my main concern and I am doing this the first time. :slight_smile:

Have a great start in your week!

Stevie

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Stevie,

As your MX records propagate (time depends on TTL time to live), mail will either go to the legacy host or Google for a period of time. Nothing will be lost. Once the propagation is complete (let’s call it 2 hours), run another delta migration to get the last few messages that went to the legacy host.