iredmail increase mailbox size

ssh into server as user root

To make attachment size 100 MB (104857600 bytes)

run following 3 commands.

postconf -e message_size_limit=104857600
postconf -e mailbox_size_limit=104857600
systemctl restart postfix


Edit php.ini file

vi /etc/php/7.2/fpm/php.ini


Change value for 3 of the following settings. It can be anything above 100 MB.

memory_limit = 256M;
upload_max_filesize = 100M;
post_max_size = 120M;

Restart php-fpm


systemctl restart php7.2-fpm


Edit roundcube configuration file

vi /opt/www/roundcubemail/config/config.inc.php


Set value for 

$config['max_message_size'] = '100M';


Edit Nginx config file

vi /etc/nginx/conf-available/client_max_body_size.conf

Set value for

client_max_body_size 100m;

restart nginx

systemctl restart nginx