Rsyslog is the Syslog server I have chosen to use. I could get Syslog-ng, but while reviewing the configuration files and having a lot of experience using the vanilla Syslog, Rsyslog seems to be the best option and the faster to work with.
By default, Rsyslog will always do the reverse resolution. This could be a double knife weapon, while sometimes it is nice having it, it makes the process slow (because the DNS takes time) and the output could be more confusing. 24-140-225-46.cpe.teksavvy.com. is harder to read than 188.8.131.52.
I will describe how I manage to disable it.
Not a fan of Amazon AWS service but I have someone who is. Although the cluster installation process it is almost the same, there are some notes to keep in mind. These notes are done thinking you are familiar with FusionPBX, FreeSWITCH, and AWS.
Roundcube is an awesome webmail. The most complete I have ever seen so far. It's fancy, look and feel combined with its IMAP access makes it not only very intuitive but to be synchronized with others clients. Well, if you are familiar with IMAP protocol you will understand why. Anyway, you can go to the Roundcube official website to read about the multiple capabilities this software has.
One thing that Roundcube lacks is a Calendar, similar to the Google Calendar. Lucky us, Kolab the open source project, has published a calendar plugin for Roundcube. I will talk here how I manage to install it under my ISPConfig3 web hosting server.