Hello, dear Fellows,
We use an Exchange2013serverto relaytwoweb applicationsvia a Front-End Transport Receive Connector, properly configured.
All messages sent by the ASP Web Application, are receivedby all the recipient domains.
But somes messages sent by the PHP Web Application are not receivedby some Domains, remaining within the queue, with error messages:
554 5.4.4 SMTP.SEND.DNS.NonExistentDomain;non existent domain
451 4.4.0 Primary Target IP responded with 421 4.7.0 "ServerName" Too many errors "Cannot achieve “Exchange Server authentication”.” Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery
failed to all alternate hosts…"
Do you think this is a PHP problem, or an Exchange problem ?
Thanks for your answers
Djamal Belouizdad
Exchange Administrator