==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):  4.4
- Deployed with iRedMail Easy or the downloadable installer?  downloadable
- Linux/BSD distribution name and version: ubuntu 18
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  pgsql
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
_ { Error: Invalid greeting from server:
12|NewNotTuring  | 421 4.7.0 mail.salesup.com Error: too many connections from xx.xx.xx.xx: 421 4.7.0 mail.salesup.com Error: too many connections from xx.xx.xx.xx
12|NewNotTuring  |     at SMTPConnection._actionGreeting (/home/ec2-user/ServiceNotification/NewTuring/node_modules/smtp-connection/lib/smtp-connection.js:756:23)
12|NewNotTuring  |     at SMTPConnection._processResponse (/home/ec2-user/ServiceNotification/NewTuring/node_modules/smtp-connection/lib/smtp-connection.js:620:16)
12|NewNotTuring  |     at SMTPConnection._onData (/home/ec2-user/ServiceNotification/NewTuring/node_modules/smtp-connection/lib/smtp-connection.js:447:10)
12|NewNotTuring  |     at Socket.emit (events.js:189:13)
12|NewNotTuring  |     at Socket.EventEmitter.emit (domain.js:441:20)
12|NewNotTuring  |     at addChunk (_stream_readable.js:284:12)
12|NewNotTuring  |     at readableAddChunk (_stream_readable.js:265:11)
12|NewNotTuring  |     at Socket.Readable.push (_stream_readable.js:220:10)
12|NewNotTuring  |     at TCP.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)
12|NewNotTuring  |   code: 'EPROTOCOL',
12|NewNotTuring  |   response:
12|NewNotTuring  |    '421 4.7.0 mail.salesup.com Error: too many connections from xx.xx.xx.xx',

How can i change the connection number because all email are sended from the same ip?

Thanks in advance