This directive is included in Dovecot configuration to avoid large number of connections from a particular user.

This option will be very helpful to mitigate some sort of attacks to this service. In this article we discuss how to manage (increase / decrease) this limit. This should be helpful in some situations.

In some situations you may get “connection refused error” while trying to access the server via POP3. The error details are pasted below:

Error

Maximum number of connections from user - IP exceeded

Form server log

22 03:55:10 host5 dovecot: pop3-login: Maximum number of connections from user+IP exceeded (mail_max_userip_connections=3): user=, method=PLAIN, rip=111.119.12.12, lip=229.222.220.17

Solution

You can see that the root cause of the error from error log 🙂 . Yes,  the “mail_max_userip_connections” value in the ‘dovecot’ configuration file is causing the issue.

Edit the configuration file and change the value to a higher one to resolve the issue.

vi /etc/dovecot.conf
---
mail_max_userip_connections = 3
---

That’s it!!

Also read:

Introduction to IAAC [Infrastructure As A Code] tools

It’s time that I had to write an article on IAAC. All giant’s infra are now set and manage as IAAC. Infrastructure As A Code is shorted as IAAC.

I hope you guys are already aware of these tools and you are already started working on that. This is a simple, straight intro to those tools. This will help you to start your journey as an automation engineer.

Now-a-days, all big infra are managing in this way, to reduce the human mistakes and deployment time.

As I mentioned, “HUMAN MISTAKES” or human errors, this is one of the main headache for managing big/medium size infra. Consider this case, you’ve 15 plus servers in your production infra. And almost 10 servers are using Nginx behind HA load balancing. You can configure all things manually in those servers with in a week and make the infra ready for production. And you have 10 peoples working as your engineers. The approach to a work is different in every person.