We just upgraded/migrated our Customer Portal to the new Customer Communities platform (but kept the Customer Portal licenses and did not migrate to new Communities licenses) and now when we create a new Community User the Welcome email is not sending at all - regardless of whether or not you check "Generate new password and notify user immediately" or not - have tried both ways on initial creation and either way it does not send the welcome email.

In the Manage Communities Setup option we do have "Send welcome email" checked and created a new email template to be used with it. The template is active and Available for Use. All of the Portal Profiles and permissions have been given access to the new Community. 

When I first Published the new Community I did not have the Manage Communities Setup option "Send welcome email" checked because I didn't want to blow up all the existing Users' inbox. We were already sending an email to customers announcing the upgraded Community. But then once it was Published and the new email template was created the setting was checked back to "Send welcome email".

What does work is after you create the new user and leave "Send welcome email" unchecked, Save it. Then go back and click 'Edit' and now check "Send welcome email". That will then send the email template set for the 'Forgot Password' and 'Change Password' options in the Manage Communities Setup options.

And apparently, SFDC changed how they treat these emails from Portal to Communities, but does not mention this in any documentation. In Portals an auto-generated password used to be contained directly in the email template, inserted at the bottom.

Now, in the new Communities, that auto-generated password is no longer included, but they changed how they do this for security reasons (winter 14 release update apparently) and instead of sending a username and password in the email they now send a special link that allows people to click and change their password.

The trick is that your forgot your password email template needs to include this special merge field (undocumented anywhere by SFDC from what I found):

{!Community_Url}

If you include that it will be replaced with a special url that allows the user to change their password and logs them in. Thread where I first found this out: http://salesforce.stackexchange.com/questions/17887/communities-forgot-password-emails

This is being successfully included in the 'Forgot Password' and 'Change Password' email templates that were created. So when I go back to the newly created User and click 'Edit' and now check "Send welcome email", it does send the email template set for the 'Forgot Password' and 'Change Password' options to the new user and they are able to get in after setting their password.

Any ideas or help you can provide??

Thanks,
Alex