Several people have reported an issue with this in the support forum but no matter how many times I tell them it's a bug no one ever submits a ticket. I guess it's up to me.

Configuration is admin activation and queue is enabled

Scenario 1 (where it works correctly): user registers and immediately receives welcome email stating that their account is currently inactive and they will get an email once an admin activates the account. The admin immediately gets the email and activates via the email link - > ucp.php?mode=activate and the user immediately gets the email notification that their account has been activated. All this works correctly and consistently b/c the emails bypass the queue.

Scenario 2 (which doesn't work correctly): user registers and immediately receives welcome email stating that their account is currently inactive and they will get an email once an admin activates the account. The admin immediately gets the email but instead activates the user via the ACP by selecting Users & Groups -> Inactive users -> marking the username in the list view (the check box) and selecting Activate. The activation notification email to the user is generated but sent to the queue instead of sent immediately like scenario 1, inconsistent and incorrect behavior. The activation notification email needs to bypass the queue just like it does in scenario 1 and scenario 3.

Scenario 3 (which now works in the latest SVN - 10118 but is broken in 3.0.5): user registers and immediately receives welcome email stating that their account is currently inactive and they will get an email once an admin activates the account. The admin immediately gets the email and activates the account in the ACP by selecting Users & Groups -> Inactive users -> selecting the user and bringing up the Overview form and using the Quick tools -> Activate account. The activation notification email is generated and immediately sent, bypassing the queue. Just an FYI...in 3.0.5 this 3rd method of activation does not generate any email notification at all. I am not sure which rev fixed that bug

Summary: All three methods of activating a user account should generate the same behavior/result, an immediate notification that bypasses the queue.