Suddenly my forum doesn’t send any email. I’m seeing the following error in logs:
/usr/local/lib/ruby/2.5.0/net/smtp.rb:539:in `initialize'
/usr/local/lib/ruby/2.5.0/net/smtp.rb:539:in `open'
/usr/local/lib/ruby/2.5.0/net/smtp.rb:539:in `tcp_socket'
/usr/local/lib/ruby/2.5.0/net/smtp.rb:549:in `block in do_start'
/usr/local/lib/ruby/2.5.0/timeout.rb:103:in `timeout'
/usr/local/lib/ruby/2.5.0/net/smtp.rb:548:in `do_start'
/usr/local/lib/ruby/2.5.0/net/smtp.rb:518:in `start'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mail-2.7.1/lib/mail/network/delivery_methods/smtp.rb:109:in `start_smtp_session'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mail-2.7.1/lib/mail/network/delivery_methods/smtp.rb:100:in `deliver!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mail-2.7.1/lib/mail/message.rb:2159:in `do_delivery'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mail-2.7.1/lib/mail/message.rb:260:in `block in deliver'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionmailer-5.2.2.1/lib/action_mailer/base.rb:560:in `block in deliver_mail'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in `block in instrument'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activesupport-5.2.2.1/lib/active_support/notifications/instrumenter.rb:23:in `instrument'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in `instrument'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionmailer-5.2.2.1/lib/action_mailer/base.rb:558:in `deliver_mail'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mail-2.7.1/lib/mail/message.rb:260:in `deliver'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionmailer-5.2.2.1/lib/action_mailer/message_delivery.rb:114:in `block in deliver_now'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionmailer-5.2.2.1/lib/action_mailer/rescuable.rb:17:in `handle_exceptions'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionmailer-5.2.2.1/lib/action_mailer/message_delivery.rb:113:in `deliver_now'
/var/www/discourse/lib/email/sender.rb:209:in `send'
/var/www/discourse/app/jobs/regular/user_email.rb:57:in `execute'
/var/www/discourse/app/jobs/base.rb:230:in `block (2 levels) in perform'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rails_multisite-2.0.6/lib/rails_multisite/connection_management.rb:63:in `with_connection'
/var/www/discourse/app/jobs/base.rb:219:in `block in perform'
/var/www/discourse/app/jobs/base.rb:215:in `each'
/var/www/discourse/app/jobs/base.rb:215:in `perform'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:185:in `execute_job'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:167:in `block (2 levels) in process'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/middleware/chain.rb:128:in `block in invoke'
/var/www/discourse/lib/sidekiq/pausable.rb:136:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/middleware/chain.rb:133:in `invoke'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:166:in `block in process'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:137:in `block (6 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/job_retry.rb:108:in `local'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:136:in `block (5 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq.rb:37:in `block in <module:Sidekiq>'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:132:in `block (4 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:243:in `stats'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:127:in `block (3 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/job_logger.rb:8:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:126:in `block (2 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/job_retry.rb:73:in `global'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:125:in `block in dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/logging.rb:48:in `with_context'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/logging.rb:42:in `with_job_hash_context'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:124:in `dispatch'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:165:in `process'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:83:in `process_one'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/processor.rb:71:in `run'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/util.rb:16:in `watchdog'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/sidekiq-5.2.5/lib/sidekiq/util.rb:25:in `block in safe_thread'