Use different email port

See added SO thread

templates/sentry.config.j2

@@ -9,6 +9,7 @@
 # Mail Server #
 ###############
 
+# https://stackoverflow.com/questions/47328056/smtpserverdisconnected-connection-unexpectedly-closed-timed-out/47328415#47328415
 mail.backend: 'smtp'
 mail.host: '{{ smtp_server }}'
 mail.port: {{ smtp_port }}

vars/email.yml

@@ -1,5 +1,5 @@
 smtp_server: 'smtp.transip.email'
-smtp_port: 465
+smtp_port: 587
 smtp_password: !vault |
           $ANSIBLE_VAULT;1.1;AES256
           34306430333263396535626334633436623532623536663134656332323239663731343230623035