Altering the maximum size for the attachment is necessary if you can’t send any attached documents via email. Plesk admins can set a memory limit to the attachment size for their Webmail accounts for Roundcube.
To Set Limit to Attachment Size
1. Connect to your Linux server via SSH.
2. Edit the directory /etc/psa-webmail/roundcube/php.ini and enter these settings:
upload_max_filesize = 100M post_max_size = 100M
3. Open the /usr/share/psa-roundcube/config/config.inc.php file.
$config['max_message_size'] = '133M';
Note: The value you mention here should be 33% higher than the value you set as the limit.
Moving on, these changes should reflect on all domains. It is why you have to modify the templates.
4. Create a new directory for the custom templates for webmail:
# mkdir -p /usr/local/psa/admin/conf/templates/custom/webmail
5. Enter/copy this template to the directory:
# cp /usr/local/psa/admin/conf/templates/default/webmail/roundcube.php /usr/local/psa/admin/conf/templates/custom/webmail/
6. Edit the FcgidMaxRequestLen directive in the custom template with the value specified in Bytes. (For example: 256MB= 268435456 Bytes)
# sed -i '/FcgidMaxRequestLen/c\FcgidMaxRequestLen 268435456' /usr/local/psa/admin/conf/templates/custom/webmail/roundcube.php
To finish things off, apply these changes within the template of all webmail accounts.
7. Run the command:
# plesk repair web -server
With this, you can easily set a memory limit to the attachment size for all Webmail accounts for Roundcube.