Sbcglobal Thunderbird account is not receiving,

email. Sending is just fine. It happened after I allowed an update. Was okay for a while, then stopped and started several more times. I changed passwords and it gathered all the lost emails and delivered them and now say not connecting again. Have deleted and reinstalled twice, checked firewall. The only thing that always works is bypassing the router, which is a pain. The router is working for everything else on this computer, and on the phone, kindle, etc. Suggestions?