To make best use of the guide to troubleshooting why SharePoint Alert emails stop working its helpful to have an little understanding of what is going on under the covers.

For our purposes Email Alerts can be split into two types

Confirmation Emails

When you first setup an alert a confirmation email is sent to the recipient of the alerts.

This email is sent immediately from the Web Front End (WFE) serving the page at that time and running under the Identity that the IIS worker process (w3wp.exe) is using.

Email Alerts

The “Windows SharePoint Services Timer” service (owstimer.exe) is responsible for various jobs including sending out email alerts

By default this runs every 5 minutes – this means that even when you set “Send e-mail immediately” its not really immediately, there could be a short wait for your emails to be sent.

What does mean for Troubleshooting?

These two types of email are being sent at different times from different components of SharePoint and often using different Identities running on different servers.

(Tip – if you are brave you can check the TimerLock table to see on which server your various timer jobs will run)

So just because you get the Confirmation Emails you can’t assume that the Email Alerts will be work (and vice-versa) :-

• There may be a problem stopping the SharePoint timer job running that doesn’t effect the confirmation emails.
• There may be a problem with the configuration of the alerts that only effects the alert emails
• Does your email infrastructure may not allow the emails to be relayed from the server the timer job runs on but does allow the WFE
• Does your anti-virus software stop emails being sent from the server/process (owstimer.exe) or even user identity that the timer service jobs run under but allows the confirmation emails

You get the idea! For troubeshooting purposes  you should treat them quite separately.

Related posts:

1. Troubleshooting SharePoint Alerts – Timer Jobs This part of the Troubleshooting SharePoint Email Alerts guide...
2. Troubleshooting SharePoint email alerts – Checking the Email Infrastructure This part of the alert troubleshooting guide will talk...
3. Troubleshooting SharePoint Alerts – Part 1 This guide will help you troubleshoot why you are...

This is one article in the larger Troubleshooting SharePoint Alerts guide

Problem

Task lists can send an email notification when a task is assigned or changed (Settings > Advanced Settings > E-Mail Notification).

If you modify the Assigned To column of the task list to “Allow multiple selections” then the email may be sent to random, incorrect recipients – some names will be crossed out (strike-through) in the email.

References

• Random emails getting sent out when changing “Assigned to” to allow multiple items

• Email Notifications and Alerts problem

To Resolve

This is a known issue and was fixed in Windows SharepPoint Services 3 Hotfix (KB948945 21st February 2008)

“On a SharePoint Server 2007 site, you modify a task in a task list. When you do this, users other than the users who are assigned to the task receive the notification e-mail message for the change.”

This fix is believed to have been included in

• WSS3 SP2 (April 24th 2009)

Related posts:

1. Troubleshooting – The date format in Alert emails is incorrect This is one article in the larger Troubleshooting SharePoint...
2. Troubleshooting – Something in the Alert emails is incorrect This is part 3 of the series on Troubleshooting...
3. Alerts can not be opened in Outlook 2007 when used with Exchange 2003 This is one article in the larger Troubleshooting SharePoint...