If you try to stat the container with something like TULEAP_FQDN=tuleap.example.com:30443 the container will not start because it will result in a incorrect setup of Postfix:
Setup Postfix
newaliases: warning: valid_hostname: invalid character 58(decimal): tuleap.example.com:30443
newaliases: fatal: file /etc/postfix/main.cf: parameter myhostname: bad parameter value: tuleap.example.com:30443