The instruction in the link below on how to install iRedMail with a remote MySQL is based on the fact that you are using a server for your MySQL.  However, AWS RDS is a managed database instance managed by Amazon; you don't have access to the underlying server to run the commands as specified in the link below. 

http://www.iredmail.org/docs/install.ir … erver.html

Any assistance will be appreciated.  Thanks.

AWS RDS does not have the option to connect as a root user. You can use the AWS RDS admin user for running the script. I have tried it and it works.

I'm continuing to have issue on a new install of -0.9.7 with remote mysql.  Database do not get created in the remotes mysql server. I'm using AWS RDS.
Below are my steps:
1. created user/passwd in remote mysql server(AWS RDS) with the appropriate permissions/privileges.
2. user is able to create database/tables in remote mysql server (AWS RDS), which means that user has appropriate permissions/privileges
3. I run the below commands b/4 the bash.sh script:
USE_EXISTING_MYSQL='YES' \
    >INITIALIZE_SQL_DATA='NO' \
    >MYSQL_SERVER_ADDRESS='mailserverdb.xx0xxxx6xxxx.eu-west-2.rds.amazonaws.com' \   (AWS RDS only have endpoint; no available server ip)
    >MYSQL_SERVER_PORT='3306' \
    >MYSQL_ROOT_USER='admin_iredmail' \
    >MYSQL_ROOT_PASSWD='xxxxxxxxx' \
    >MYSQL_GRANT_HOST='XX.XXX.XXX.XX' \
    bash iRedMail.sh

*****No I do not get "ERROR 1045 (28000): Access denied"*****

4. The installation wizard will go thru the necessary screens:
    Welcome and thanks for your use (Yes)
    Default mail storage path (accept default)
    Preferred web server (apache)
    Choose preferred backend used to store mail accounts (there's no option for mysql so I choose mariadb; I'm using mysql in my remote db server)
    Your first mail domain name (example.com)
    Password for the mail domain administrator (xxxxx)
    Optional components
   
5. Continue? [y|N]y
********************************************************************
* Start iRedMail Configurations
********************************************************************
[ INFO ] Create self-signed SSL certification files (2048 bits).
[ INFO ] Generate Diffie Hellman Group with openssl, please wait.
[ INFO ] Create required system account: vmail, iredadmin, iredapd.
[ INFO ] Configure Apache web server.
[ INFO ] Configure PHP.
[ INFO ] Configure MariaDB database server.
[ INFO ] Setup daily cron job to backup SQL databases with /var/vmail/backup/backup_mysql.sh
[ INFO ] Configure Postfix (MTA).
[ INFO ] Configure Dovecot (POP3/IMAP/Managesieve/LMTP/LDA).
[ INFO ] Configure ClamAV (anti-virus toolkit).
[ INFO ] Configure Amavisd-new (interface between MTA and content checkers).
[ INFO ] Configure SpamAssassin (content-based spam filter).
[ INFO ] Configure iRedAPD (postfix policy daemon).
[ INFO ] Configure iRedAdmin (official web-based admin panel).
[ INFO ] Configure Fail2ban (authentication failure monitor).
[ INFO ] Configure Roundcube webmail.
[ INFO ] Configure Awstats (logfile analyzer for mail and web server).

*************************************************************************
* iRedMail-0.9.7 installation and configuration complete.
*************************************************************************

6. [ INFO ] Disable SELinux in /etc/selinux/config.
< Question > Would you like to use firewall rules provided by iRedMail?
< Question > File: /etc/firewalld/zones/iredmail.xml, with SSHD port: 22. [Y|n]y

7. < Question > Would you like to use MySQL configuration file shipped within iRedMail now?
< Question > File: /etc/my.cnf. [Y|n] n

8.  When I go to the remote mysql server, no database(s) is created.

Any thoughts?  Thank you

Thank you very much.  Using the 'YES' worked.  However, new iRedMail install created the databases on the remote server, and also on the iRedMail server.  Should I be worried about two the databases in two locations?  When I try to delete the ones on the local iredmail server, it deleted it also on the remote AWS RDS server.  Any thoughts.  Thank you very much.

I have done this few times on new servers fresh new installs, and I get similar results.  Could there be a bug?  Below are my servers:
1.  Remote MYSQL server is AWS RDS.  Servername or endpoint is:
     a. mailserverdb.xx0xxxx6xxxx.eu-west-2.rds.amazonaws.com (listening on port 3306
     b. admin_iredmail with privileges/permissions created on this server, and able to connect with no issues

2.  iRedMail Server is: AWS Red Hat Enterprise Linux 7.3 (fresh OS);
    On this server I run:

    USE_EXISTING_MYSQL='mailserverdb.xx0xxxx6xxxx.eu-west-2.rds.amazonaws.com' \       (AWS RDS servername)
    MYSQL_SERVER_ADDRESS='mailserverdb.xx0xxxx6xxxx.eu-west-2.rds.amazonaws.com' \
    MYSQL_SERVER_PORT='3306' \
    MYSQL_ROOT_USER='admin_iredmail' \
    MYSQL_ROOT_PASSWD='xxxxxxxxxx' \
    MYSQL_GRANT_HOST='101.10.10.101' \
    bash iRedMail.sh

db and users are created on the remote and the iredmail server.  See outputs below:

From iRedMail server:
MySQL [(none)]> select user, host from mysql.user;
+----------------+--------------+
| user           | host         |
+----------------+--------------+
| admin_iredmail | %            |
| naijamail      | %            |
| amavisd        | 172.31.0.173 |
| iredadmin      | 172.31.0.173 |
| iredapd        | 172.31.0.173 |
| roundcube      | 172.31.0.173 |
| vmail          | 172.31.0.173 |
| vmailadmin     | 172.31.0.173 |
| iredmailadmin  | localhost    |
| mysql.sys      | localhost    |
| rdsadmin       | localhost    |
+----------------+--------------+

From my remote MYSQL server:
# mysql -h mailserverdb.xxxxxxxxxxxxxxeu-west-2.rds.amazonaws.com -P 3306 -u xxxxxxxx -p

MySQL [(none)]> select user, host from mysql.user;
+----------------+--------------+
| user           | host         |
+----------------+--------------+
| admin_iredmail | %            |
| naijamail      | %            |
| amavisd        | 172.31.0.173 |
| iredadmin      | 172.31.0.173 |
| iredapd        | 172.31.0.173 |
| roundcube      | 172.31.0.173 |
| vmail          | 172.31.0.173 |
| vmailadmin     | 172.31.0.173 |
| iredmailadmin  | localhost    |
| mysql.sys      | localhost    |
| rdsadmin       | localhost    |
+----------------+--------------+
11 rows in set (0.00 sec)

during installation of iRedMail, there's a place that asks for, "Would you like to use MySQL configuration file shipped within iRedMail now?". 
File: /etc/my.cnf. [Y|n].  I choose 'y'

During the iRedMail Configurations section,  I get this error message:
"ERROR 1419 (HY000) at line 398 in file: '/root/iRedMail-0.9.7/runtime/iredmail.sql': You do not have the SUPER privilege and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)"

It should be "USE_EXISTING_MYSQL=YES" (or "NO"), but any value which is "NO" will be treated as "YES".

Please set "log_bin_trust_function_creators=1" in my.cnf of AWS RDS.