Transporter Suite issues while migrating from generic IMAP to Exchange 2007
Yesterday we encountered an issue during the last sync from an generic IMAP server to an Exchange Server 2007 SP3 server on Windows Server 2008 R2 (there were reasons not to migrate to Exchange 2010 that are beyond the scope of this post ). We used the Microsoft Transporter Suite.
Although the initial big bulk sync was performed without a hitch, after the migration weekend some new mails still had to be synced from the IMAP server (this was not planned, but due to an error by our domain registrar…). Unfortunately now the migration failed with the following errors (the identifier varied with each error):
An item has failed property validation and will be ignored.
Error details:Required property is empty.
Web searches showed a lot of other people who had these issues. Most of them were resolved by editing the web.config of the EWS virtual directory as described in KB953526, which adds a executionTimeout and maxRequestLength value. Which has to be saved in ANSI format BTW.
Some issues were resolved be recreating the EWS virtual directory or by adding a TargetServer value in the migration CSV.
But not in our case and seemingly a lot of other cases if I searched correctly. We checked whether there were items larger than the value in web.config and the Global Settings of Exchange with Get-MailboxFolderStatistics, but that wasn’t the case.
Finally we reversed everything that had changed in between the two migration points. It turned out that an IIS redirect on the Default Website to /owa was the culprit. Removing the redirect resolved our issue and the differences in mail could be successfully migrated.
Ps. A thank you to my coworker Hans Lenze for bringing this issue to my attention!