On Thu 2016-Apr-28 09:48:09 +0200, Piotr <piotr.1234@interia.pl> wrote:

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

You've given us damn near zero information to go on. Are you with Cisco? Or managing some of these "certain domains" to which cisco.com addresses cannot send? It sounds like the latter and that seems more plausible as I'd be pretty surprised to find a cisco.com postmaster sending a vague request like this to nanog. I don't really get how TAC would be involved; have you tried postmaster@cisco.com? Assuming that you *are* the receiving side, what logs do you have on this? What are the names of these "certain domains"? Are they all under the same administrative control / same MXs (I'm assuming yes)? This also seems like something for mailop[1] rather than nanog. Fair warning; they're using Let's Encrypt and are having trouble with the rollover, so the cert's expired again.

best regards, Peter

-- Hugo Slabbert | email, xmpp/jabber: hugo@slabnet.com pgp key: B178313E | also on Signal [1] https://chilli.nosignal.org/mailman/listinfo/mailop