Verify Request (VRFY)

When the Internet Mail Service communicates with an SMTP host, it may be asked to identify a user. This is done with the SMTP verify command (VRFY). The verify command asks the receiver to identify whether a user can be reached through the receiving host. The response will include the mailbox of the user and a full name.

The following is an example of a verify request for the user "smith." The response is the full name and the SMTP address for the user Renee Smith.

Send: VRFY smith
Received: 250 Renee Smith <renees@abcd.COM>

Enabling VRFY

The verify request for the Internet Mail Service is disabled by default. Disabling the VRFY command is of interest to mail administrators concerned with spoofing. The VRFY command is one method of querying a server for valid SMTP addresses.

1. Open Regedit.exe or Regedt32.exe.
2. Open the following registry keys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\
MSExchangeIMC\Parameters
3. If you are using Regedit.exe, choose Edit, and then choose New DWORD Value. If you are using Regedt32.exe, choose Edit, and then choose Add Value.
4. If you are using Regedit.exe, type EnableVRFY; under Value data, type 1. If you are using Regedt32.exe, type EnableVRFY; under Data Type, choose REG_DWORD.
5. If you are using Regedt32.exe, under Data, type 1.