While doing the AD object merge, GroupWise Migrator for Exchange will run into the 20 character limit for the sAMAccountName attribute (Pre-Windows 2000 username) if the username is longer than 20 characters.
sAMAccountName attribute has a size of less than 20 characters.
1) Pre-create the mailbox-enabled user on the target Exchange server
2) In the UsersToMerge.csv and AddressTranslation.csv files, for the above user:
* specify the full GroupWise username in the "Userid" column
* specify the truncated (20 character or less) sAMAccountName in the "NdsUsername" column
* specify the correct SMTP address (to match that of the target mailbox) in the "TargetAddress" column
3) Use GroupWise Migrator for Exchange to "migrate users" (jump right to this step and do not perform AD Object Merge for this user)
More information on sAMAccountName attribute is available on the MDSN site: