Source package thunderbird-lightning-3.3-3.el7.src.rpm used by EPEL7 does not support ppc64le (little endian) Is it possible to have a newer version supporting this architecture ? thunderbird-lightning-3.3-5 was the first version supporting ppc64le. see secondary koji http://ppc.koji.fedoraproject.org/koji/packageinfo?packageID=11748
thunderbird-lightning-3.3-5.el7 has been submitted as an update for Fedora EPEL 7. https://admin.fedoraproject.org/updates/thunderbird-lightning-3.3-5.el7
Package thunderbird-lightning-3.3-5.el7: * should fix your issue, * was pushed to the Fedora EPEL 7 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=epel-testing thunderbird-lightning-3.3-5.el7' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-EPEL-2015-6005/thunderbird-lightning-3.3-5.el7 then log in and leave karma (feedback).
thunderbird-lightning-3.3-5.el7 has been pushed to the Fedora EPEL 7 stable repository. If problems still persist, please make note of it in this bug report.