Confirmation Emails are not sent

Summary

When registering a new user or when requesting a confirmation email, i do not recieve an email. However, sending an email through rails console works, as well as requesting password reset emails.

Steps to reproduce

Either, register as a new user or go to login screen of GitLab and request confirmation email for an already registered user.

Example Project

Running GitLab Docker Container on CentOS 7, no SELinux, Docker version 17.06.2-ce, build cec0b72

What is the current bug behavior?

No confirmation email gets sent.

What is the expected correct behavior?

I recieve an confirmation email

Relevant logs and/or screenshots

Output when successfully sending a password reset email. When sending a confirmation email, nothing happens here.

root@gitlab:/# tail -f /var/log/gitlab/sidekiq/current
2018-01-10_15:31:40.05834 2018-01-10T15:31:40.057Z 498 TID-ors2y9s94 ActionMailer::DeliveryJob JID-b6a708e27ba976bda079ec32 INFO: start
2018-01-10_15:31:40.11869 2018-01-10T15:31:40.118Z 498 TID-ors2y9s94 ActionMailer::DeliveryJob JID-b6a708e27ba976bda079ec32 INFO: done: 0.061 sec

Output when requesting a confirmation email:

root@gitlab:/# tail -f /var/log/gitlab/nginx/gitlab_access.log
192.168.5.24 - - [10/Jan/2018:15:44:25 +0000] "GET /users/confirmation/new HTTP/1.1" 200 3152 "http://gitlab/users/sign_in" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
127.0.0.1 - - [10/Jan/2018:15:44:40 +0000] "GET /help HTTP/1.1" 200 29420 "" "curl/7.56.1"
192.168.5.24 - - [10/Jan/2018:15:44:41 +0000] "POST /users/confirmation HTTP/1.1" 302 98 "http://gitlab/users/confirmation/new" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
192.168.5.24 - - [10/Jan/2018:15:44:41 +0000] "GET /users/almost_there HTTP/1.1" 200 2490 "http://gitlab/users/confirmation/new" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"

Results of GitLab environment info

Expand for output related to GitLab environment info 
System information
System:
Current User:   git
Using RVM:      no
Ruby Version:   2.3.5p376
Gem Version:    2.6.13
Bundler Version:1.13.7
Rake Version:   12.3.0
Redis Version:  3.2.11
Git Version:    2.14.3
Sidekiq Version:5.0.4
Go Version:     unknown


GitLab information
Version:        10.3.3
Revision:       888cf31
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     postgresql
URL:            http://gitlab
HTTP Clone URL: http://gitlab/some-group/some-project.git
SSH Clone URL:  ssh://git@gitlab:2222/some-group/some-project.git
Using LDAP:     no
Using Omniauth: no


GitLab Shell
Version:        5.10.2
Repository storage paths:
  • default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check 
Checking GitLab Shell ...


GitLab Shell version >= 5.10.2 ? ... OK (5.10.2)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:root, or git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ... can't check, you have no projects
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Redis available via internal API: OK


Access to /var/opt/gitlab/.ssh/authorized_keys: OK
gitlab-shell self-check successful


Checking GitLab Shell ... Finished


Checking Sidekiq ...


Running? ... yes
Number of Sidekiq processes ... 1


Checking Sidekiq ... Finished


Reply by email is disabled in config/gitlab.yml
Checking LDAP ...


LDAP is disabled in config/gitlab.yml


Checking LDAP ... Finished


Checking GitLab ...


Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... skipped (no tmp uploads folder yet)
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ... can't check, you have no projects
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.5 ? ... yes (2.3.5)
Git version >= 2.7.3 ? ... yes (2.14.3)
Git user has default SSH configuration? ... yes
Active users: ... 2


Checking GitLab ... Finished