XFOR: IMC Accepts SMTP Address with Space While IMS Does Not

Administrators of Microsoft Exchange managing multiple versions of the Internet Mail Connector may notice that in older versions, address nomenclature not normally seen in Internet Mail messages are accepted inbound, but not accepted inbound with later versions. The 553 malformed address: return code will be seen.

As the Microsoft Exchange product matures, the Internet Mail Connector by design is more strict with respect to address formatting.

The Internet Mail Connector can be slackened with respect to allowing uncommon addresses inbound. The following registry entry can be employed.

1.	Start Registry Editor (Regedt32.exe or Regedit.exe, depending on your version of Windows NT).
2.	Under the HKEY_LOCAL_MACHINE subtree, go to the following subkey: System/CurrentControlSet/Services/MSExchangeIMC/Parameters
3.	On the Edit menu, click Add Value, and then use the following entry: Value Name: AcceptMalformed821Adrs Data Type: REG_DWORD Value: 1
4.	Cycle the Internet Mail Connector when done