Hi All,
I use the .NET version but I do have a copy of the Win32 version installed for testing. Upon reviewing this thread I did some research and found the following:
http://www.gordano.com/kb.htm?q=319
The VRFY clause is a method of verifying the existence of a user on a mail server. Normally you an either verify the existence of particular usr or use a wildcard verify (VRFY *) to ask the server to return a complete list of users. This latter option is rarely enabled on mail servers nowadays as it was used widely by spammers to harvest email addresses, indeed most mail servers nowadays can disable the VRFY option altogether. Gordanos products disable the VRFY command by default.
http://www.gordano.com/kb.htm?q=980
EXPN can be used to request, or expand, a mailing list on the remote server. The sending server can query the receiving server to see if it will accept Enhanced SMTP commands. If it does it will send back to the connecting server the enhanced commands it will accept. If EXPN is listed, it can be used. p> If the receiving server accepts EXPN, your string should identify a particular mailing list. The multiline response may include the full name of all users and must provide the mailboxes on the mailing list.
That being said, I tested my Win32 version of ArGo for these comands. They are rejected by the server. I used the Samp Spade v1.1.4 (win32 version), which has an SMTP digg feature. You can see the results for yourself:
11/07/08 14:25:59 SMTP Verify maillist@192.168.1.21, at 192.168.1.21
Contacting 192.168.1.21
220 mail.topcatcomputing.dev ArGoSoft Mail Server Pro for WinNT/2000/XP, Version 1.8 (1.8.9.3)
HELO example.com
250 Welcome, 192.168.1.21 .168.1.21], pleased to meet you
VRFY maillist@192.168.1.21
502 Unknown command
Doesn't want to talk to us
RSET
250 Reset state
EXPN maillist@192.168.1.21
550 List maillist@192.168.1.21 not found
Doesn't want to talk to us
RSET
250 Reset state
MAIL FROM:<spade@example.com>
250 Sender "spade@example.com" OK...
RCPT TO:<maillist@192.168.1.21>
554 Mailing list contains remote users. Authentication required for relay
Doesn't want to talk to us
RSET
250 Reset state
QUIT
221 Aba he
11/07/08 14:25:16 SMTP Verify steve@192.168.1.21, at 192.168.1.21
Contacting 192.168.1.21
220 mail.topcatcomputing.dev ArGoSoft Mail Server Pro for WinNT/2000/XP, Version 1.8 (1.8.9.3)
HELO example.com
250 Welcome, 192.168.1.21 .168.1.21], pleased to meet you
VRFY steve@192.168.1.21
502 Unknown command
Doesn't want to talk to us
RSET
250 Reset state
EXPN steve@192.168.1.21
550 List steve@192.168.1.21 not found
Doesn't want to talk to us
RSET
250 Reset state
MAIL FROM:<spade@example.com>
250 Sender "spade@example.com" OK...
RCPT TO:<steve@192.168.1.21>
250 Recipient "steve@192.168.1.21" OK...
RCPT TO:<bogus85916@192.168.1.21>
550 User unknown <bogus85916@192.168.1.21>
Doesn't want to talk to us
RSET
250 Reset state
QUIT
221 Aba he
Did these commands return results in your Security Audit?
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