ODME behaviour during the migration job

Question

1. i have a migration job to migrate a G Suite mailbox (approx 20Gb) to o365. Given Google's bandwidth throttling, it should take days for the migration to complete. My question is during these few days when the migration job is ongoing, when new mails arrive at the source mailbox, will it be migrated as well? 
 2. Second question is after the migration job is completed, when i rerun the same job, is it only the delta changes gets migrated? 
 
 Thanks in advance 
 Ang

Trevor Taegder · Accepted Answer

Thank you for posting to the On Demand Migration for Email (ODME) forum. I understand you have a couple of questions regarding the migration behavior or ODME. Here are your answers: 
 
1.) ODME works its way through the mailbox folder tree when migrating from G Suite, or any other source. For example, once the root of the Inbox has been migrated, then ODME moves on to subfolders. Any email received into the root of the Inbox after the Inbox has been processed, will not be migrated until you run the migration again. During the final migration pass, ODME should be used to set forwarding on the source mailbox, so that any new mail received is forwarded to the new target while the migration is ongoing. The following section of the ODME Users Guide provides more details: 
 
 support.quest.com/.../6 
 
2.) You are correct, ODME will not migrate items that have already been migrated. However, there are a couple of caveats to this. If a user moves emails around in the source during the migration period, then the those emails that were moved in the source may be duplicated in the target, one copy in the original location and then another copy in the new location. Additionally, ODME will not migrate updates or changes to items that have already been migrated, so it is generally suggested that calendar, tasks and contacts be migrated as part of the final migration, to ensure that the latest up to date information is migrated to the target. 
 
Please let me know if you have any additional questions or need any additional clarification.