I have migrated from Exchange 2003 to Exchange 2007 and updated my address lists and email address policies. I started decommissioning the Exchange 2003 server and immediately new calendar appointments are undeliverable for all users. I checked the ExchangeLegacyDN as described in the Microsoft KB article and those are correct. I have created two new mailboxes on the 2007 server and still get the same undeliverable messages. I am running Exchange SP1 Rollup 7. I have disabled the virus scanning software. The three errors recorded on the Exchange 2007 server after each appointment sent are 8199 8213 and 8230.
A communication failure occurred during the delivery of this message. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or provide the following diagnostic text to your system administrator
#550 4.4.1 STOREDRV.Deliver: connection timed out. The following information should help identify the cause: "MapiExceptionUnableToComplete:16.18969:961D0000, 17.27161:0000000066020000000000007D00000000000000, 255.23226:00000000, 255.27962:7A000000, 255.27962:0A000000, 255.27962:0E000000, 255.27962:0A000000, 255.27962:0C000000, 255.17082:00040480, 0.18273:00000000, 4.21921:00040480, 255.27962:FA000000, 255.1494:10000000, 255.1238:4F000000, 6.21970:0F010480020185670F010480, 6.21970:0F01048040008F660F010480, 6.21970:0F010480020186670F010480, 6.21970:0F01048040008F660F010480, 6.21970:0F010480020186670F010480, 6.21970:0F01048040008F660F010480, 6.21970:0F010480020186670F010480, 4.8916:E7FAFFFF, 4.14219:E7FAFFFF, 4.15243:E7FAFFFF, 4.12427:E7FAFFFF, 4.8916:E7FAFFFF, 4.14219:E7FAFFFF, 4.15243:E7FAFFFF, 4.12427:E7FAFFFF, 4.9867:E7FAFFFF, 6.21970:0F01048000801336E7FAFFFF, 4.31473:0F010480, 6.21970:0F01048000801336E7FAFFFF, 4.31473:0F010480, 4.6926:00040480, 255.1750:00040480, 255.31418:2B0A0000, 0.21457:2B0A0000, 4.19665:00040480". ##