Postfix Lost connection analysis: 421 4.4.2 host error: timeout exceeded

[Leer este post en español]

In this post we’ll show the analysis of another common error for smtp status code 421 4.4.2 host Error: timeout exceeded which refers to network or connection problems between SMTP servers. The symptoms you may observe is the your Postfix (IMSVA) server is not able to accept all incoming mails and sender server is starting to have queuing problems. Continue reading

Wireshark Filters

Wireshark is an application that allows you to capture network traffic, this is very useful when you need to troubleshoot problems or just to understand how an specific application works. In this post you will find some filters that may help you to correctly interpret complete conversations or specific network packets. Continue reading