How to Migrate GSuite to O365 when there are millions of messages in the Inbox? (4254294)

GSuite allows millions of messages with the same label, But Microsoft has a limit of One Million messages per folder. 

If a label (Inbox) has millions of messages in it how do we migrate it?

For this example we will assume that there are 4.5 million messages in the Inbox.

Split messages into chunks by date, assign a unique label to each portion, keep Inbox label on every message

1. Search messages for a certain date range #1 in Inbox, assign it label1. Keep Inbox label on every message
2. Search messages for a certain date range #2 in Inbox, assign it label2. Keep Inbox label on every message
3. And so on to LabelN

+++Note+++

In this configuration, if we migrate a plan as is, we will duplicate the whole source volume – the 1^st copy will go source Inbox to target "Inbox”, the 2^nd copy will be copied into the “LabelN” target folder.

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In order to avoid this, we need to ignore the Inbox label on the source. The exclude filter in the plan settings will do the job.