[Info-vax] %MAIL-E-INVITMLEN ?

[Snowshoe]

Email sent to a VMS system is getting bounced with a message like the 
following:

Date: Wed, 29 Feb 2012 19:46:47 -0500 (EST)
Message-Id: <12022919464727_422 at xxxxx.com>
From: Postmaster at XXXXX.COM
To: <original sender>
Subject: Returned mail


---- Transcript of session follows ----

%%%%%%%%%%%%                   29-FEB-2012 19:46:47.19  %%%%%%%%%%%%
%MAIL-E-INVITMLEN, invalid item length

---- Recipients of this delivery ----

<name at XXXXX.COM> (bounced)

---- Unsent message follows ----

<snip message>

What is this %MAIL-E-INVITMLEN error? Googling finds some _old_ 
instances of this issue, but it appeared to have been fixed.  This 
system is:
HP TCP/IP Services for OpenVMS Industry Standard 64 Version V5.7 - ECO 1
Is it back from the dead? Has HP fixed it (again)?

Like in the old instances, the destination address is SET FORWARDed to 
another username.