500 5.5.0 Syntax error - line too long

We are using VB .NET code to send out emails.  Occasionally we get one back with the above error.  What does it mean?
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In your Windows\System32\logfiles folder you should see a directory for SMTP..
Find the log that has the date of the error, open the log with notepad and do an edit/find search for "500 " or "5.5.0 "
You want to find the command that was issued, so it should be on the same line or the one above it just prior to the 5.5.0 error.
You may have to open IIS or in ESM's Protocols/SMTP branch and augment the details for the logging you are collecting.
You basically want to add all logging options using w3c format.
Once you have found the offending command, review your VB code to find the anomaly.

rkanterAuthor Commented:
I forgot to point out that the email is addressed to several people.  Some get it without a problem.  There error is generated by the recipients email server not by ours.
rkanterAuthor Commented:
When it says 'line too long," what line iint the email s it talking about?
Generally anything issued in the command...

Basically an SMTP session start with
1. HELO or EHLO (extended SMTP)
2. Then it issues a FROM command when you provide the senders address
3. Then it issues an RCPT TO: command to designate the recipient, this command will have e-mail addresses in it etc..
4. Then it should issue a DATA command, followed by the message body..
5. Then it should issu a QUIT

So really, the likely places your code is messing up on are either CR carriage returns between commands, or the FROM, RCPT TO or DATA commands.. the EHLO and QUIT commands don't pass any parameters so I doubt those commands would have any relation to the problem..  

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rkanterAuthor Commented:
That helps.  I amm going out of town until Monday.  I will let you know what I find.
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