You should see a message on the screen after submitting the bug that shows the users that were sent emails and those users who were excluded.

If the assignee was excluded you are looking at one of the following 2 reasons:

  1. Each user can configure whether they receive emails for different event. Go to Preferences/Email Preferences to see the options.
  2. Additionally all email can be disabled for a user by the administrator. Go to Administration/Users find the user and look at the Bugmail Disabled field.

If the assignee was on the send to list and they didn’t receive it you need to look at your email system. Have the user check their spam folders etc. Some email hosts will reject messages that claim to be from the domain they manage, but were not actually sent from that domain.

For example if you set the Bugzilla parameter mail_from to “me@example.com” many email servers will not allow those messages though. The way to fix this is to change the mail_from parameter to something like “mybugzilla@devzing.com”