I create rails app deployed on Heroku.
also, exception_notification
gem enabled.
when it is on development setup ActionMailer to Gmail, everything is fine a
The issue was raised on the main repository (see here), but so far was not addressed.
You might want to take a look at this fork to the exception_notification gem, specifically this commit which tries to deal with the problem: https://github.com/alanjds/exception_notification/commit/048fc6be972189e62ca3b9453d19233ec5773016
To use this fork I pointed the gem to it, like so:
Gemfile:
gem 'exception_notification', git: 'git://github.com/alanjds/exception_notification.git'
This solved the issue for me.