Message from customer keeps getting marked bad header

[Alvin]

On 13/09/2012 17:42, Jeffrey Walls wrote:
> We have a very important customer who is getting pissed off that all his
> PO’s sent from his ERP system keep getting bounced.
> 
> The issue is both our CSR and his person sending the PO are both on the
> To: line.
> [...]
>             < kolab.browntransmission.com #5.6.0 smtp; 554-5.6.0 Reject,
> id=03482-10 - BAD_HEADER: Duplicate 554 5.6.0 header field: "To">
> 
> [...]
> To: jwalls at browntransmission.com
> To: brian.xxxxx at xxxxxx.com

Interesting error. It should indeed be
To: jwalls at browntransmission.com, brian.xxxxx at xxxxxx.com

The ERP system sending the mail is broken. It's possible to let Kolab
pass the mail on, but what will your mail clients do with it?