I'm a programmer, not a sys-admin, but my customer's sys-admins are not being helpful and after much googling I still can't find the answer to this.
My Java application gets the following response from my customer's MS Exchange following EHLO
EHLO PMNDEV3.prd.abc 250-PYTHON3.prd.abc Hello [220.127.116.11] 250-SIZE 20971520 250-PIPELINING 250-DSN 250-ENHANCEDSTATUSCODES 250-AUTH 250-8BITMIME 250-BINARYMIME 250-CHUNKING 250-XEXCH50 250 XSHADOW
Note that the 250-AUTH response has no parameters, so my software library (JavaMail) understandably says that it can't authenticate as there are no supported mechanisms advertised per RFC 4954
My question is why is this so? Is there perhaps some other non ESMTP authentication happening that is causing no AUTH mechanisms to be advertised?