I have two event recievers setup on a list in 2010.

The first is a ItemAdded reciever that works every time:

<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Receivers ListTemplateId="10000">
      <Receiver>
        <Name>ListItemReceiverItemAdding</Name>
        <Type>ItemAdding</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
        <Class>SSW.TipDontRant.Sharepoint.ListItemReceiver</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>
  </Receivers>
</Elements>

The second is an Email event reciever that I have only preiodicaly got to work.. In the 30-40 attempts to debug the applicaiton I have only had it work in 2 cases.

<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Receivers ListTemplateId="10000">
      <Receiver>
        <Name>EmailReceiverEmailReceived</Name>
        <Type>EmailReceived</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
        <Class>SSW.TipDontRant.Sharepoint.EmailReceiver</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>
  </Receivers>
</Elements>

I have attached to the OWSTimer and the ListTemplateId is indeed correct.

On checking the log as sugested I found the follwoing error:

12/11/2009 17:12:54.01  OWSTIMER.EXE (0x2314)                       0x046C  SharePoint Foundation           Monitoring                      nasq    Medium      Entering monitored scope (Timer Job job-email-delivery) 7b525bbb-0972-4115-97b1-19b1d94ff8c5
12/11/2009 17:12:54.03  OWSTIMER.EXE (0x2314)                       0x046C  SharePoint Foundation           E-Mail                          6873    Warning     An error occurred while processing the incoming e-mail file C:inetpubmailrootDrop24c6872e01ca7a8500000003.eml. The error was: Object reference not set to an instance of an object..    7b525bbb-0972-4115-97b1-19b1d94ff8c5
12/11/2009 17:12:54.03  OWSTIMER.EXE (0x2314)                       0x046C  SharePoint Foundation           E-Mail                          6871    Information The Incoming E-Mail service has completed a batch.  The elapsed time was 00:00:00.0190038.  The service processed 1 message(s) in total.  Errors occurred processing 1 message(s): Message ID: <B05256D324B3D540853A95FF2AD9B257801F931C81@mooncalf>    7b525bbb-0972-4115-97b1-19b1d94ff8c5
12/11/2009 17:12:54.03  OWSTIMER.EXE (0x2314)                       0x046C  SharePoint Foundation           Monitoring                      b4ly    Medium      Leaving Monitored Scope (Timer Job job-email-delivery). Execution Time=23.4762559268986 7b525bbb-0972-4115-97b1-19b1d94ff8c5

Its a little dificult to read here, but the important bit I think is:

An error occurred while processing the incoming e-mail file C:inetpubmailrootDrop24c6872e01ca7a8500000003.eml. The error was: Object reference not set to an instance of an object.. 7b525bbb-0972-4115-97b1-19b1d94ff8c5

Which does not tell me much! I do not think that it an error with my code, as it would throw within Visual Studio. I can confirm that emails sent to a document library work correctly as well.

1. Has anyone else had these problems?
2. Has anyone managed to get this to work consitantly?

[UPDATE] I left my code over the weekend, did not touch it at all, and now it is working! This seams to be very flacky on Sharepoints part.

So, I now have the line of my code that is failing (note that I did not get this far before) and it is on a reference to an external assembly for which I have opened another question Sharepoint 2010 Project package: Cannot add a new project output assembly to the package