Mail stops working after migration from 9.2.7 to 9.3.0

Our mails stops working when I update from 9.2.7 to 9.3.0. We received this error: OpenSSL::SSL::SSLError: hostname "<url>" does not match the server certificate. But when I tried with this: Notify.test_email('destination_email@address.com', 'Message Subject', 'Message Body').deliver_now this works well. Do you know what's wrong ?

gitlab | ==> /var/log/gitlab/sidekiq/current <==
gitlab | 2017-06-23_10:34:49.28232 2017-06-23T10:34:49.282Z 453 TID-otwoc51to EmailsOnPushWorker JID-2a3fe5c1db710aee46e799d2 INFO: start
gitlab | 2017-06-23_10:34:49.66250 2017-06-23T10:34:49.662Z 453 TID-otwoc51to EmailsOnPushWorker JID-2a3fe5c1db710aee46e799d2 INFO: fail: 0.38 sec
gitlab | 2017-06-23_10:34:49.66284 2017-06-23T10:34:49.662Z 453 TID-otwoc51to WARN: {"context":"Job raised exception","job":...................

gitlab | 2017-06-23_10:34:49.66313 2017-06-23T10:34:49.662Z 453 TID-otwoc51to WARN: OpenSSL::SSL::SSLError: hostname "<url>" does not match the server certificate
gitlab | 2017-06-23_10:34:49.66314 2017-06-23T10:34:49.662Z 453 TID-otwoc51to WARN: /opt/gitlab/embedded/lib/ruby/2.3.0/openssl/ssl.rb:318:in `post_connection_check'
gitlab | 2017-06-23_10:34:49.66319 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:944:in `connect'
gitlab | 2017-06-23_10:34:49.66320 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:863:in `do_start'
gitlab | 2017-06-23_10:34:49.66321 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:852:in `start'
gitlab | 2017-06-23_10:34:49.66321 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:584:in `start'
gitlab | 2017-06-23_10:34:49.66322 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:479:in `get_response'
gitlab | 2017-06-23_10:34:49.66324 /opt/gitlab/embedded/lib/ruby/2.3.0/net/http.rb:456:in `get'
gitlab | 2017-06-23_10:34:49.66324 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_loaders/network_loader.rb:9:in `load'
gitlab | 2017-06-23_10:34:49.66327 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:37:in `block in load_css'
gitlab | 2017-06-23_10:34:49.66329 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:36:in `each'
gitlab | 2017-06-23_10:34:49.66330 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:36:in `load_css'
gitlab | 2017-06-23_10:34:49.66331 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:21:in `css_for_url'
gitlab | 2017-06-23_10:34:49.66332 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:17:in `block in css_for_doc'
gitlab | 2017-06-23_10:34:49.66332 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:17:in `map'
gitlab | 2017-06-23_10:34:49.66334 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/css_helper.rb:17:in `css_for_doc'
gitlab | 2017-06-23_10:34:49.66337 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/customized_premailer.rb:14:in `initialize'
gitlab | 2017-06-23_10:34:49.66338 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:87:in `new'
gitlab | 2017-06-23_10:34:49.66339 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:87:in `premailer'
gitlab | 2017-06-23_10:34:49.66340 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:76:in `generate_html_part'
gitlab | 2017-06-23_10:34:49.66340 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:52:in `generate_html_part_replacement'
gitlab | 2017-06-23_10:34:49.66343 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:24:in `perform'
gitlab | 2017-06-23_10:34:49.66343 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/premailer-rails-1.9.2/lib/premailer/rails/hook.rb:8:in `perform'
gitlab | 2017-06-23_10:34:49.66344 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/mail-2.6.5/lib/mail/mail.rb:243:in `block in inform_interceptors'
gitlab | 2017-06-23_10:34:49.66345 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/mail-2.6.5/lib/mail/mail.rb:242:in `each'
gitlab | 2017-06-23_10:34:49.66347 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/mail-2.6.5/lib/mail/mail.rb:242:in `inform_interceptors'
gitlab | 2017-06-23_10:34:49.66352 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/mail-2.6.5/lib/mail/message.rb:225:in `inform_interceptors'
gitlab | 2017-06-23_10:34:49.66354 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/mail-2.6.5/lib/mail/message.rb:235:in `deliver'
gitlab | 2017-06-23_10:34:49.66354 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/actionmailer-4.2.8/lib/action_mailer/message_delivery.rb:85:in `deliver_now'
gitlab | 2017-06-23_10:34:49.66355 /opt/gitlab/embedded/service/gitlab-rails/app/workers/emails_on_push_worker.rb:89:in `send_email'
gitlab | 2017-06-23_10:34:49.66356 /opt/gitlab/embedded/service/gitlab-rails/app/workers/emails_on_push_worker.rb:55:in `block in perform'
gitlab | 2017-06-23_10:34:49.66356 /opt/gitlab/embedded/service/gitlab-rails/app/workers/emails_on_push_worker.rb:53:in `each'
gitlab | 2017-06-23_10:34:49.66357 /opt/gitlab/embedded/service/gitlab-rails/app/workers/emails_on_push_worker.rb:53:in `perform'
gitlab | 2017-06-23_10:34:49.66360 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:204:in `execute_job'
gitlab | 2017-06-23_10:34:49.66360 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:175:in `block (2 levels) in process'
gitlab | 2017-06-23_10:34:49.66362 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:128:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66363 /opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/sidekiq_status/server_middleware.rb:5:in `call'
gitlab | 2017-06-23_10:34:49.66364 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66365 /opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/sidekiq_middleware/request_store_middleware.rb:6:in `call'
gitlab | 2017-06-23_10:34:49.66365 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66368 /opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/sidekiq_middleware/memory_killer.rb:17:in `call'
gitlab | 2017-06-23_10:34:49.66369 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66369 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/server/active_record.rb:15:in `call'
gitlab | 2017-06-23_10:34:49.66370 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66372 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sentry-raven-2.4.0/lib/raven/integrations/sidekiq.rb:7:in `call'
gitlab | 2017-06-23_10:34:49.66372 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:130:in `block in invoke'
gitlab | 2017-06-23_10:34:49.66376 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/middleware/chain.rb:133:in `invoke'
gitlab | 2017-06-23_10:34:49.66377 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:174:in `block in process'
gitlab | 2017-06-23_10:34:49.66378 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:146:in `block (6 levels) in dispatch'
gitlab | 2017-06-23_10:34:49.66378 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/job_retry.rb:97:in `local'
gitlab | 2017-06-23_10:34:49.66379 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:145:in `block (5 levels) in dispatch'
gitlab | 2017-06-23_10:34:49.66380 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq.rb:36:in `block in <module:Sidekiq>'
gitlab | 2017-06-23_10:34:49.66381 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:141:in `block (4 levels) in dispatch'
gitlab | 2017-06-23_10:34:49.66384 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:220:in `stats'
gitlab | 2017-06-23_10:34:49.66385 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:136:in `block (3 levels) in dispatch'
gitlab | 2017-06-23_10:34:49.66385 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/job_logger.rb:8:in `call'
gitlab | 2017-06-23_10:34:49.66386 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:135:in `block (2 levels) in dispatch'
gitlab | 2017-06-23_10:34:49.66387 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/job_retry.rb:72:in `global'
gitlab | 2017-06-23_10:34:49.66388 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:134:in `block in dispatch'
gitlab | 2017-06-23_10:34:49.66388 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/logging.rb:32:in `with_context'
gitlab | 2017-06-23_10:34:49.66389 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:133:in `dispatch'
gitlab | 2017-06-23_10:34:49.66390 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:173:in `process'
gitlab | 2017-06-23_10:34:49.66393 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:85:in `process_one'
gitlab | 2017-06-23_10:34:49.66394 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/processor.rb:73:in `run'
gitlab | 2017-06-23_10:34:49.66395 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/util.rb:17:in `watchdog'
gitlab | 2017-06-23_10:34:49.66396 /opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/sidekiq-5.0.0/lib/sidekiq/util.rb:26:in `block in safe_thread'