Email send action fails: Cron has been running for more than an hour and is most likely stuck
I think that your PHP configuration is not letting cron finish. Turn off poormanscron, then delete your cron entries in your MySQL database:

DELETE FROM `variable` WHERE name = 'cron_semaphore';
DELETE FROM `variable` WHERE name = 'cron_last';


Then go to admin/reports/status and click on your PHP version to see the output of phpinfo(). What is the max execution time? What is the memory limit? You'll want to change those values to higher numbers, then verify that they are indeed different on this page, then run cron manually at admin/reports/status. 

To change these 2 values in PHP, create (or edit) php.ini in the webroot of your site and add (or modify):

max_execution_time = 300
memory_limit = 256M


Obviously feel free to try whatever numbers you'd like here. Ideally you don't want to leave the memory limit very high if you don't need to.