SharePoint Incoming emails not picked up

Incoming emails not picked up in MOSS 2007

 When trying to setup email enabled document libraries, we setup the front end server with the SMTP service. On sending emails we saw the emails getting deposited into the C:\Inetpub\MailRoot\Drop folder. However the emails were not getting picked up and routed to the service. We tried to restart the Timer Service, gave folder permissions and nothing seemed to work. Upon checking the event logs we found the following entries

A critical error occurred while processing the incoming e-mail drop folder.
The error was: Value cannot be null. Parameter name: path.

Source: Windows SharePoint Services 3
Category: EMAIL
Event ID: 6872;

2)
“The Execute method of job definition
Microsoft.SharePoint.Administration.SPIncomingEmailJobDefinition (ID
d7c219ba-839d-4580-adc2-fa512a8cb833) threw an exception. More information is
included below.
Value cannot be null.
Parameter name: path”

Source: Windows SharePoint Services 3
Category: TIMER
Event ID: 6398″

This looked like the incoming email drop folder was not setup properly in the Central Admin Console. We checked and sure enough the drop folder was empty. Setting that value fixed this error. To set the drop folder

Central Admin-> Incoming email settings

Click Advanced and type in the email drop folder.

 Here is a great whitepaper on how to setup incoming emails (Whitepaper)