The AutoEmailPrimaryAddress is a choice variable (email|emailpro|B_email|cardnumber|OFF), but the default is set to '0' in the sysprefs.sql installer. This prevents emails from sending unless the value is manually changed in the system preferences editor.
I'd add that the AutoEmailPrimaryAddress preference is used by more than just the AutoEmailOpacUser preference and such shouldn't be lumped together with it. (patch waiting for sign off).
Created attachment 2806 [details] signed off patch1
Patch pushed please test
This bug is mentioned in: Bug 5460: AutoEmailPrimaryAddress set to invalid value in sysprefs.sql http://lists.koha-community.org/pipermail/koha-patches/2010-November/013132.html
Created attachment 2829 [details] [review] Split AutoEmailPrimaryAddress and AutoEmailOpacUser sysprefs Patch to split display of these options in the syspref editor, for less confusion to librarians.
This bug is mentioned in: Bug 5460: AutoEmailPrimaryAddress set to invalid value in sysprefs.sql http://lists.koha-community.org/pipermail/koha-patches/2010-December/013171.html