I'm seeing this in 6.0.5.

2018-04-09 11:23:22,300 ERROR [NotificationSender:thread-3] [plugin.notifications.dispatcher.NotificationErrorRegistryImpl] addError Error sending notification to server '<Unknown>'(-1) for INDIVIDUAL task (resent 1 times): Error sending to individual '8a81e92b5c6db79d015c6dbb2e300814' on server 'System Mail'
NotificationException: javax.mail.MessagingException: Exception reading response;
  nested exception is:
	java.net.SocketTimeoutException: Read timed out

We are also requesting a fix for version 5.8.17

same error on 5.8.x

Hi Richard, there are entries in the log file that indicate that emails are being sent to inactive users, according to https://confluence.atlassian.com/display/CONFKB/Email+notifications+trigger+a+NoSuchElementException+in+the+logs?focusedCommentId=781194392&#comment-781194392. The users are disabled in Active Directory, and we are using Crowd to read the Active Directory. There are two pages that are sending the emails, and only one watcher on one of those pages. I'm not sure why the emails are being sent. How can we identify the user from the log file value for user '8ae784ab4de7ac44014de8f684650042'?

2015-09-30 11:34:02,689 ERROR [NotificationSender:thread-2] [plugin.notifications.dispatcher.NotificationErrorRegistryImpl] addError Error sending notification to server '<Unknown>'(-1) for INDIVIDUAL task (resent 4 times): Error generating message for server 'System Mail' on medium 'mail' for user '8ae784ab4de7ac44014de8f684650042'. 

darrell.bush which kinds of notifications are being sent to deactivated users in your system? How are those users being deactivated? Is it by marking them disabled in LDAP, deactivating them directly in Confluence user management, or removing their "use confluence" permission? We believe we've resolved the issue for shares, but we could easily have missed other notification types - sorry about that. I'll reopen this, and ensure that we get coverage for all the notification types in Confluence before this issue is marked as resolved again.

This is marked as Resolved-Fixed. What is the resolution? I am still seeing this in version 5.8.4.

Affected: 5.6.3 and 5.7.3

I'm increasing the priority of this due to the fact that it can potentially send emails to people who shouldn't get them.

I agree the priority should be much higher on this. Especially if there is no a workaround.

This is actually a data security risk and should be a much higher priority.

I have only just stumbled upon this issue as I have found that ex-employees are receiving emails on our current projects (receiving company sensitive data) due to this issue.

You can argue that all employees should be signing to Confluence with their work email addresses (which we would deactivate), however starting as a small company means we have some cases like this.

Linking to https://jira.atlassian.com/browse/CONF-22070?focusedCommentId=272555&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-272555. As Joel points out in that ticket, this problem is more apparent with the Atuowatch feature.

This issue is borderline between "improvement" and "bug". I am changing it to "bug", cause it sounds like sending mail to disabled users is the wrong thing to do

Any insight into when this might be addressed? This problem is occurring on Confluence 2.6.2 (standalone). Thanks.