Plesk mail not working 10024: Connection refused

On a Plesk mail server, when sending/reciving email, it fail with following error in /var/log/maillog

Aug 11 19:49:28 vmi274961 postfix/smtp[29276]: E413C3320265: to=, relay=none, delay=0.47, delays=0.47/0/0/0, dsn=4.4.1, status=deferred (connect to 127.0.0.1[127.0.0.1]:10024: Connection refused)

To fix, reinstall email-security extension.

plesk bin extension --uninstall  email-security

Verify mail works. If all good, you can reinstall the Plesk mail security extension from Plesk admin

root@vmi274961:~# plesk bin extension --list
advisor - Advisor
baqend - Speed Kit
composer - PHP Composer
configurations-troubleshooter - Webserver Configurations Troubleshooter
dgri - Imunify QuickPatch
digitalocean-spaces-backup - DigitalOcean Spaces Backup
diskspace-usage-viewer - Diskspace Usage Viewer
dnssec - Plesk DNSSEC
domain-connect - Domain Connect
email-security - Plesk Email Security
firewall - Firewall
git - Git
google-drive-backup - Google Drive Backup
grafana - Grafana
heavy-metal-skin - Skins and Color Schemes
kernelcare-plesk - KernelCare
letsencrypt - Let's Encrypt
monitoring - Advanced Monitoring
new-relic - New Relic - Application Performance Monitoring
pagespeed-insights - Google PageSpeed Insights
panel-migrator - Plesk Migrator
plesk-mobile - Plesk Mobile Center
repair-kit - Repair Kit
revisium-antivirus - ImunifyAV
site-import - Site Import
social-login - Social Login
sslit - SSL It!
symantec - DigiCert SSL
traffic-monitor - Domain Traffic Monitor
watchdog - Watchdog
wp-toolkit - WordPress Toolkit
xovi - SEO Toolkit
root@vmi274961:~# plesk bin extension --uninstall  email-security
The extension was successfully removed.
root@vmi274961:~# 

If its mail configuration issue, you can run

plesk repair mail

Plesk Mail not working amavis error

See Plesk