I would think that this is a recipient server issue. Is the CC'd address going to the same server?
On 9/4/2020 7:31 PM, David Bray wrote:
Hi With this message, I'm right to think that: * this is nothing to do with the sending side, * It has to be the serving side that is issuing this message, * there is no possible way that adding a CC address (or any other address, even an additional to address) could affect sending to the primary recipient Cheers David Bray e. da...@brayworth.comSeptember 3, 2020 2:00 PM, "David Bray" <da...@brayworth.com <mailto:da...@brayworth.com?to=%22David%20Bray%22%20<da...@brayworth.com>>> wrote:Hi I have an issue where 1. A client sends an email to a remote server 2. and cc's a copy to someone else under these circumstance I get: delivery 3555: deferral: <ip>_does_not_like_recipient./Remote_host_said:_451_relay_not_permitted!/Giving_up_on_<ip>./ it does eventually go through but the delay is several hours * If I test without the CC it goes through straight away * The CC'ed mail is delivered staright away * it only affects this server Their server has a signature if this helps: * signature spamexpert-2.servers.netregistry.net ESMTP Exim 20200825.1020 Thu, 03 Sep 2020 06:57:02 +0300 Cheers David Bray e. da...@brayworth.com <mailto:da...@brayworth.com>
