contact with mail support for domain cisco.com

[Piotr <piotr.1234 () interia pl>]

Hi,

There is a problem with sending emails from employees in @cisco.com 
domain to some certain domain. Emails in opposite direction pass without 
problem. No errors, warnings or any other logs at cisco's employees 
desktop.. We checked popular rbls, spamhauses, senderbase etc. Other 
domains on the same MX cluster receive emails from @cisco.com..

I try to get help in many ways ( cisco tac, a few  account managers, 
channel partners) but without success..

Big thanks for contact via email:   peter.handke.1966 at gmail.com
or any other advice

best regards,
Peter