==== Required information ====
- iRedMail version (check /etc/iredmail-release):  Current
- Linux/BSD distribution name and version: Debian
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Web server (Apache or Nginx): Apache
====

Google Cloud prevents access on ports 25, 587, etc. I can receive mail just fine, but due to the block, I am unable to send mail with this server I am working with a client on.

I made the following changes to master.cf for postfix to open port XXXX, which is also open in Google Cloud's firewall, and IPTables.
XXXX inet n       -       n       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o content_filter=smtp-amavis:[127.0.0.1]:10026

However, it is reportedly still trying to send mail on port 25, which it cannot do since the port is blocked. I cannot test it currently as I am unable to login to the server for some reason with my phone (Outlook), though Outlook on Desktop seems to be working.