I have just upgraded to 1.5.1 and have a problem sending emails, I simply get the following and emails are not sent:
It seems that the application stuck because of an error.
Nothing is written to the application/logs when ENABLE_DEBUG=true is set.
I have tried PHP Mail and Sendmail, both are working for other applications on the server.
This might have nothing to do with anything but there are a lot of lines like this in the log:
ERROR - 2017-05-01 22:52:17 --> Could not find the language line "enabled"