Error returned when emailing Messagelabs clients

Hi,

[I posted in a topic but I think it may be best to post as a new topic]

My client has encountered this error sending an email to a contact:

x-originating-ip: [96.69.125.106]

I believe this is the same issue as on the beginning of this thread.

Earlier this week I was brought on to clean a malware infection and remove blacklisting on their domain. This may be a leftover from this?

edit: as have others I checked http://ipremoval.sms.symantec.com/lookup/ but it does not recognize the ip.

Can you help clarify?

Many thanks