All of a sudden out of nowhere certain people get the following message when sending mail to one of my mail servers: { Diagnostic-Code: SMTP; 505 5.7.3 Client was not authenticated }There have been no changes to the mail server or DNS. Mail server is running Imail v.6.04 I have another mail server set up identically that does not have this problem. When someone sends from hotmail or some other domains that is the error. When someone sends from Bellsouth or Netscape webmail the error pops up.
Any SMTP gurus out there?
Any SMTP gurus out there?