Installing a Let's Encrypt certificate for your qmail and dovecot servers

March 21, 2018 Roberto Puzzanghera 14 comments

More info:

Here is how to install and configure a valid certificate from Let's Encrypt for your qmail and dovecot servers. The installation will be done by certbot.

Certbot is part of EFF’s effort to encrypt the entire Internet. Secure communication over the Web relies on HTTPS, which requires the use of a digital certificate that lets browsers verify the identity of web servers (e.g., is that really google.com?). Web servers obtain their certificates from trusted third parties called certificate authorities (CAs). Certbot is an easy-to-use client that fetches a certificate from Let’s Encrypt—an open certificate authority launched by the EFF, Mozilla, and others—and deploys it to a web server.

Limiting the number of emails sent by a given auth-user/domain/IP

October 24, 2017 Roberto Puzzanghera 8 comments

If you want to avoid the risk of compromising your server because of accounts who are sending messages indiscriminately to the world, due to the fact that their password was violated in some way, then you can take advantage of Luca Franceschini's rcptcheck-overlimit.sh script, which has to be used in conjunction with the rcptcheck patch (a patch derived by Luca himself from an original work of Jay Soffian).

Since in 2016 Luca has decided to merge his combo with my big patch, he is giving his personal contribution to it. He fixed many bugs and added new important patches and functionalities, often writing himself the code. The script shared here is just the last one and it's quite surprising (at least for me) to observe how many things are performed putting together just 20 lines.

Slackware guest on Linux-VServer

July 5, 2016 Roberto Puzzanghera 4 comments

Linux-Vserver is an open source software which acts as a virtual private server implementation done by adding operating system-level virtualization capabilities to the Linux kernel.