We have been working hard behind the scenes to improve the public folder migration experience and are very glad to announce even more improvements. These improvements will help you in faster onboarding of public folders to Exchange Online.
Mailbox Replication Service (MRS) performs certain clean-up tasks during the finalization phase of the migration. If a clean-up task fails, it is retried for up to 4 hours. Ultimately it will delay the finalization of the migration request. And the delay will be even more if there are a greater number of migration jobs in the batch.
We have made improvements to the clean-up tasks that take place during finalization of the public folder migration. After these improvements we have observed large public folder migrations, which historically could have taken 3-4 days, are completed in only 15-20 hours.
Previously, if a migration batch encountered a non-fatal warning, a warning which could be ignored, it would still be marked as Failed. In such scenarios, a tenant admin would have to re-submit the migration batch, potentially causing significant delays in migration.
We have made improvements in this area. If the migration batch completes with those same non-fatal warnings, the batch is treated as completed successfully. This allows for faster completion of public folder migrations, without compromising the data integrity.
These improvements are being rolled out to Exchange Online and should be available to your tenant soon.
We’ve love to hear your feedback and please feel free to ask any questions via the comments section below.