Gitlab email not work

The email function of gitlab is not working at my institute.
It was installed by a former colleague in our institute with docker following the instruction:

Here is the code of how gitlab was installed :

docker run --name=gitlab_redis -tid sameersbn/redis:latest;
docker run --name=gitlab_mysql -tid -e ‘DB_NAME=gitlabhq_production’ -e ‘DB_USER=gitlab’ -e ‘DB_PASS=password’ -v /opt/gitlab/mysql:/var/lib/mysql sameersbn/mysql:latest;
docker run --name=gitlab -d -itd
–link gitlab_mysql:mysql
–link gitlab_redis:redisio
-e ‘GITLAB_PORT=10080’
-e ‘GITLAB_SSH_PORT=10022’
-p 10022:22 -p 10080:80
-v /home/git/gitlab/:/home/git/data
-e ‘’
-e ‘SMTP_PASS=9894664’
-e ‘
-e ‘
-e ‘SMTP_PORT=587’
-e ‘’
-v $(which docker):/bin/docker
-v /opt/gitlab/log:/var/log/gitlab

the is the mailbox of the colleague. When he left, was deleted. was also deleted, and now created with password “gitlab.local.pass”.

I am wondering if there is a way to change SMTP_USER to and SMTP_PASS to “my pass” without affecting the current functions of gitlab.

Another question: I think in the code above, there is no setting of the password for gitlab accessing the mailbox “”, but had sent the emails to us. Is there any need to set the password and how?

Any hint could be appreciated.