What a shock - CentOS.

[NJW]

I think it is better to install what you want (SAMBA, OpenChange) separately. Then you will also know something about what you just set up.

This. Plus, there's no licence cost.

Zentyal only claims to offer support for Outlook 2007/2010, which although nice, sort of leaves out the poor sods using Outlook 2013?

That's the inevitable result of reverse-engineering closed protocols. The open alternative just becomes stable and the goalposts are moved. It needs a concerted effort by an established player (e.g., RHEL) to produce a complete alternative solution – alternative, not just-about-compatible. The fact that no-one has done it indicates that the effort-reward equation doesn't fit. Exchange Server doesn't do anything that's unattainable by anything else, but its installed base makes it pretty much unconquerable unless Microsoft goes into administration.

 

[coffee]

You configure from scratch every time? My LAN Debian server installation is 10 years old and has had two in-place upgrades. I have changed the motherboard, migrated to RAID-1 for /home and an SSD for / during that time. Config file changes are flagged by the installer (the same as happens during updates, if the .conf changes) and you have the opportunity to stick with the old, change to the new or edit as you go.

I have approached each upgrade with trepidation and allowed a full weekend, but it has always (so far ...) been back in use in under two hours, start to finish. That's including a full image of the root drive (/home was imaged the day before – it's 2 GB). One of those upgrades included a change from sysv to systemd and from i386 to amd64. I did a test run in a VM before starting that one for real.

No, What I am saying is that some updates to the operating system will replace config files or certain switches will become obsolete and this can affect your config file. You can backup your config files all you want (and I do) but sometimes things change and your config file actually becomes obsolete. At times during an update it will ask if you want to replace a config file or whatever and you have to pay particular attention to that.

 

[fencepost]

I'm always wary of "direct replacement" open source options - I love them, BUT if it saves $100/month on licensing costs while adding $250/month in billable administration/tweaking/fixing time then I feel it's a poor choice for the customer.

As far as Exchange replacements and licensing costs, it's probably worth looking HARD at the Office365 hosted Exchange options - figure out how much licensing for in-house is going to cost, guesstimate your charges for setup and ongoing maintenance, then calculate how much for doing the hosted option and a guesstimate on your time spent with administration on that. Don't forget to include RMM charges and cost of backup for the in-house server. The hosted option may turn out to have a better break-even for your customer than you'd expect, and you still get some income from managing that for them and for reselling.

I have one customer that's price-sensitive on some of that and what we did there is just put in an in-office Kolab server. Almost all of their users are just using webmail, so I don't have to worry about PSTs or "Exchange replacement" compatiblity with Outlook. I'm thinking about dropping a few more of those in for clients using per-user PSTs with no calendaring, etc.

 

[trevm999]

I have one customer that's price-sensitive on some of that and what we did there is just put in an in-office Kolab server. Almost all of their users are just using webmail, so I don't have to worry about PSTs or "Exchange replacement" compatiblity with Outlook. I'm thinking about dropping a few more of those in for clients using per-user PSTs with no calendaring, etc.

Wow, Kolab looks pretty cool.

 

[fencepost]

It's nice in that they aren't trying to build it all from scratch themselves - the previous version used the Horde webmail interface, but Roundcube is more polished and I think a cleaner internal design so they switched to that and I believe support the main developer. After some of the email snooping stuff a couple years ago they also started their own online "secure" mail service (aka not hosted within the USA) based on Kolab, so you know they're putting in work to be sure it scales.

It's using other open source products (or forks) internally as well - Cyrus IMAP but with some tweaks to allow storage of items (like calendar events) that aren't traditional messages, stuff like that.