I was getting this: Event Type: Warning Event Source: Windows SharePoint Services 3 Event Category: E-Mail Event ID: 6873 Date: 7/2/2007 Time: 11:13:23 AM User: N/A Computer: PERSEUS Description: An error occurred while processing the incoming e-mail file C:\Inetpub \Mailroot\Drop\7eb0c1d001c7bcbb00000009.eml. The error was: Unknown alias.. The list e-mail alias was correct. The magic that seemed to work for me was: 1) Running Timer service as NT AUTHORITY\NETWORK SERVICE. 2) Removing and re-establishing the incoming e-mail settings on the list that wasn't working.