disable ssl for mysql client apps

I have set up SSL for mysql replication. The problem is, that it makes problems on the other local apps which use mysql.

Like postfix:

Jul 25 23:00:22 srv1 postfix/proxymap[3141]: warning: connect to mysql server 127.0.0.1: SSL connection error: unable to verify peer checksum
Jul 25 23:00:22 srv1 postfix/trivial-rewrite[3353]: warning: virtual_mailbox_domains: proxy:mysql:/etc/postfix/mysql-virtual_domains.cf: table lookup problem
Jul 25 23:00:22 srv1 postfix/trivial-rewrite[3353]: warning: virtual_mailbox_domains lookup failure

or amavis:

Jul 25 23:08:12 srv1 amavis[5625]: (05625-01) (!)connect_to_sql: unable to connect to DSN 'DBI:mysql:database=dbispconfig;host=127.0.0.1;port=3306': SSL connection error: unable to verify peer checksum

and also pureftp

Jul 25 23:02:42 srv1 pure-ftpd: (?@2a02:810c:XXXXXXXX) [ERROR] The SQL server seems to be down [SSL connection error: unable to verify peer checksum]

Because I dont need local encryption, i want to disable it, but I dont know how.
I have only set a cnf entry for the clients with:

[client]
#ssl-ca=/etc/letsencrypt/live/mydomain/chain.pem
#ssl-mode=DISABLED
ssl=0

But without luck. For postfix I found in the docs this note:

Postfix 3.1 and earlier don’t read [client] option group settings
unless a non-empty option_file or option_group value are specified. To
enable this, specify, for example “option_group = client”.

So I added to all /etc/postfix/mysql-*.cf files the option_group syntax. But after the restart it is the same problem..

When I disable ssl on the server, the problems are gone. But I want to have ssl for security of the replication.

Any Ideas?