It is visible from the logs that Migration Manager agents are deleting mailboxes, even if those mailboxes have been created by Migriation Manager, by dirsync.
Why do the agents delete those mailboxes and why are they being deleted without having the agent to configured so?
Does this mean that the agent could possibly delete any mailboxes which already contain some mail data?
How do agents handle mailboxes which are already present on Exchange 2010 server? "Forbiddelmailbox"
Mail Target and Calendar Synchronization Agents do not synchronize target mailboxes that exist prior to exchange migration. Is there any way to change this behavior?
The following error message is found in the MTA log:
2/7/2008 4:36:34 PM CMBMConn::SetMailboxInfoE2K Warning 4807 Cannot create mailbox '/o=organization/ou=organization unit/cn=Recipients/cn=username' on the target server because the mailbox already exist (ForbidMailboxDeletion = 1).
Below is an excerpt from Exch User Guide which explains the behavior and how the ForbidDelMailbox is being used when migrating to Exchange 2010 (in combination with ForbidDelMailbox2010)
FOR LEGACY AGENTS ONLY
FOR LEGACY AGENTS ONLY
Synchronization Specifics in Exchange 2010
How to Avoid Incompatible Mailboxes
An Exchange 2010 server may create unrequested empty mailboxes for mailbox-enabled users that have no mailboxes. This behavior was not present in previous Exchange versions.
The resulting mailboxes are incompatible with Migration Manager and cannot be used by it during Exchange migration. Instead of relying on Exchange to create mailboxes, you should delete such automatically created mailboxes and use mailbox creation settings in your migration project. Mailboxes created by Migration Manager are fully supported.
However, new Exchange 2010 mailboxes should not be deleted indiscriminately, because valid target mailboxes might be deleted in the process. The ForbidDelMailbox 2010 parameter has been introduced to facilitate cleanup.
Previously, the ForbidDelMailbox parameter in the mail target agent's INI file was the only setting responsible for preserving or removing target mailboxes whoseMailboxInfoparameter did not match the same parameter in the source mailbox. The ForbidDelMailbox parameter is a precaution against the deletion of mailboxes that are in actual use in the target environment. By default, it is set to 1 so that non-matched target mailboxes are not deleted.
The additional ForbidDelMailbox 2010 parameter affects only Exchange 2010 target mailboxes. This parameter can have one of the following values:
0 Delete the new mailbox, but only if it is empty.
1 Let the ForbidDelMailbox parameter define what to do with the new mailbox, but only if the mailbox is empty. Otherwise, do not delete the mailbox.
The ForbidDelMailbox 2010 parameter is not included in the mail Target agent's INI file by default, and its value is assumed to be 0.
| ForbidDelMailbox | ForbidDelMailbox2010 | Action for E2003 - E2010 | Action for E2000 |
| 1 | 0 | Mbx size = 0: delete mailbox. | do not delete mailbox |
| Mbx size not =0: do not delete mailbox | |||
| 1 | 1 | do not delete mailbox | do not delete mailbox |
| 0 | 0 or 1 | delete mailbox. | delete mailbox. |
First row is the default setting (ForbidDelMailbox=1 and ForbidDelMailbox2010=0)
Attached screenshot also demonstrates and explains all possible combinations of settings and what they will accomplish.
Changing the Setting
There are two way to change this Setting. One is temporary for the specific MTA and/or CSA experiencing the error and the second is across the whole of QMM.
