Mysql – Centos 7 Postfix install using MYSQL 5.7 which replaced mariadb

Sorry to disturb you, but I've a problem I can't seem to get around.

I'm trying to install Postfix on a new server which was needed to move to for more space/memory, the old server had 256MB of RAM and was quite old.

I'm pretty novice at it and have spent pretty much most of today/night trying to figure out how to get this working. The old server had MYSQL 5.5.36 so figured there might be unexpected issues if we changed to MariaDB and opted to upgrade to MYSQL 5.7.18 for the new server. We don't really have a dedicated dev ops team so I can't defer to them.

This is my error:

    yum install postfix
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.seas.harvard.edu
 * epel: epel.mirror.constant.com
 * extras: ftp.osuosl.org
 * updates: mirror.trouble-free.net
 * webtatic: us-east.repo.webtatic.com
Resolving Dependencies
--> Running transaction check
---> Package postfix.x86_64 2:2.10.1-6.el7 will be installed
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
Package 1:mariadb-libs-5.5.52-1.el7.x86_64 is obsoleted by mysql-community-libs-compat-5.7.18-1.el5.x86_64 which is already installed
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
Package 1:mariadb-libs-5.5.52-1.el7.x86_64 is obsoleted by mysql-community-libs-compat-5.7.18-1.el5.x86_64 which is already installed
--> Finished Dependency Resolution
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (base)
           Requires: libmysqlclient.so.18()(64bit)
           Available: 1:mariadb-libs-5.5.52-1.el7.x86_64 (base)
               libmysqlclient.so.18()(64bit)
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (base)
           Requires: libmysqlclient.so.18(libmysqlclient_18)(64bit)
           Available: 1:mariadb-libs-5.5.52-1.el7.x86_64 (base)
               libmysqlclient.so.18(libmysqlclient_18)(64bit)
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest


# yum install postfix --skip-broken
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: linux.cc.lehigh.edu
 * epel: epel.mirror.constant.com
 * extras: ftp.osuosl.org
 * updates: mirror.solarvps.com
 * webtatic: us-east.repo.webtatic.com
Resolving Dependencies
--> Running transaction check
---> Package postfix.x86_64 2:2.10.1-6.el7 will be installed
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
Package 1:mariadb-libs-5.5.52-1.el7.x86_64 is obsoleted by mysql-community-libs-compat-5.7.18-1.el5.x86_64 which is already installed
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
Package 1:mariadb-libs-5.5.52-1.el7.x86_64 is obsoleted by mysql-community-libs-compat-5.7.18-1.el5.x86_64 which is already installed

Packages skipped because of dependency problems:
    2:postfix-2.10.1-6.el7.x86_64 from base

Obviously I can see that the mariadb-libs are obsoleted by the mysql-community libs, but I've completely removed? mariadb

yum remove mariadb-libs
Loaded plugins: fastestmirror
No Match for argument: mariadb-libs
No Packages marked for removal

Is there anyway, I can fix this to either:

• Get Postfix installed and move on
• Maybe change to Mariadb (we have PROD data here, will this cause issues)
• Maybe downgrade to MYSQL 5.5 (don't really want to do this because going backwards isn't ideal).

Any help would be much appreciated. Users currently can't receive password reset emails from the application.

Thanks in advance.