Recently I’ve had couple of complaints that users were suddenly unable to send attachments to SharePoint 2010 doc library. After trying to dig out something on this topic in SharePoint log I’ve discovered following in ULS:

An error occurred while processing the incoming e-mail file C:\Inetpub\mailroot\Drop\1314011501cd7e5600000014.eml. The error was: Unknown alias: <alias>
E-mail cannot be delivered because site is over quota or locked for editing. Site URL: http://<siteURL&gt;

It seems that after applying AprilCU for SharePoint issue appeared, and it affects Farms that does not have any value set for quota

So, I simply did the following:

  • SharePoint Central Administration
  • Application Management
  • Configure quotas and locks
  • Site Quota Information section
  • Set a limit (higher than current calue) on “Limit site storage to a maximum of:”
  • Press “OK”.

And the problem was gone. Also remove any failed emails from C:\inetpub\mailroot\Drop because SharePoint Timer service “Microsoft SharePoint Foundation Incoming E-Mail timer job” will try to send them.