As others have suggested, you might wish to look at your RBLs, if you have any configured, and check your customers' ip addresses against them.
What is the spam filtering package that you have disabled only to leave IMF? On Sat, Feb 13, 2010 at 7:32 AM, Silvio L. Nisgoski <nisgo...@gmx.de> wrote: > No, no 3rd party anti-spam . > > > ----- Original Message ----- > *From:* Maglinger, Paul <pmaglin...@scvl.com> > *To:* MS-Exchange Admin Issues <exchangelist@lyris.sunbelt-software.com> > *Sent:* Friday, February 12, 2010 6:43 AM > *Subject:* RE: Disappearing e-mail messages.... > > Do you have an anti-spam solution somewhere in the chain that’s dropping > the email? > > > > *From:* Silvio L. Nisgoski [mailto:nisgo...@gmx.de] > *Sent:* Thursday, February 11, 2010 6:57 PM > *To:* MS-Exchange Admin Issues > *Subject:* Disappearing e-mail messages.... > > > > Hello, > > > > Could someone suggest where can I look for the reasons for some > disappearing messages ? Customers that were able to send email to our > people are saying they sent the emails, but our people say they never > received. This started some time ago. Nothing in logs, nothing in spam > filters. I will disable all filtering to see if it impacts , but don´t think > so. Have perused through the 1k messages / day of spam, but the "phantom" > messages are not here. > > > > Now , I know that users cannot be trusted not to delete a Mailer Daemon > message without reading, but this is happening with people who used to > communicate via email normally since a long time ago. Any suggestion for > searching the problem ? System is 2003 - R2 with Exchange 2003. > > > > > > Thanks, > > > > Silvio. > > > >