Not work the config SMTP to send email

[superbully]

First of all, I would like to thank you for your contribution to this project.
I have deployed your project perfectly, it work fine. When i pass the enverionment for smtp in the docker-compose, it work, i can see inside the container, in the configuration postfix, the variable "relayhost", "inet_protocols", ... . apparently everything is fine.
I have tried to send a email from container console, with the command mail, but not work and obviously, nagios notifications do not work.
Also, i don´t find the log mail from postfix container .....
Any ideas ? What I might be doing wrong ?
Thank you so much.

[wolframroesler]

Not sure what your problem is but in order to send e-mails I had to add the following to my Dockerfile:

RUN echo "my_smtp_password" >/etc/postfix/sasl_passwd && \
    chmod 600 /etc/postfix/sasl_passwd && \
    postmap /etc/postfix/sasl_passwd && \
    rm /etc/postfix/sasl_passwd && \
    postconf -e 'myhostname = my_host_name.example.com' && \
    postconf -e 'relayhost = my_smtp_server.example.com:587' && \
    postconf -e 'smtp_sasl_auth_enable = yes' && \
    postconf -e 'smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd' && \
    postconf -e 'smtp_sasl_security_options =' && \
    /etc/init.d/postfix restart