Post Sony Pictures a lot of companies have become super wary of it.
I know a good number of high profile companies (including in the HN sense) that won't let you conduct dealings with them via any cloud service. Potential clients/partners really do ask what email service you're using quite early these days, the only universally acceptable answer is self hosted (either Exchange or something else), which strikes me as crazy considering how difficult to do properly that is, but there we are.
Was there a specific slack/Sony Pictures connection, or do you just mean the general increase in awareness of third party risks?
I actually agree about self-hosted communications even when you use other cloud services; I've been thinking about something in this space a lot recently, and the alternative to BYOD. Not sure if this is just being whining about Sony or an actual market, though, so it might not be a worthwhile product.
In general. I had run into it prior to SPE, but it's far more common now, even with not particularly tech savvy companies. However, were I to name some of the tech companies that have this requirement there would be a lot of coffee getting into keyboards.
BYOD doesn't seem to be an issue as long as you can demonstrate their data isn't leaking to cloud services.
Mail is a good service to host yourself. With a couple of digital ocean boxes you are golden. Set up your backup MX to just hold mail and deliver it to your primary MX.
SMTP is forgiving and you can have many hours of outage of a primary mail server without losing mail.
I wish I did. Personally I'm very much in the Google ecosystem, and this has been a repeat point of friction. Thus far the approach has been to go on site with a trusted intermediary that has the required infrastructure, but it's not sustainable.
Not much scares me technically like the idea of ineptly deploying a mailserver.
Zarafa is excellent (and works with MS Outlook if you need that).
Edit (to elaborate more): it's open source, has a very nice web ui, supports pop/imap/outlook, does activesync and mobile push, uses other standard opensource software (postfix, mysql), is easy to backup, comes with good documentation, is simple enough to get up and running (there are pre-built deb and rpm packages), integrates with LDAP and you can get a paid support contract if you need/want one. Their open source site is here: https://community.zarafa.com/
I'm not affiliated with them - just a happy sysadmin whose managed lots of Zarafa installs in the past.
I know a good number of high profile companies (including in the HN sense) that won't let you conduct dealings with them via any cloud service. Potential clients/partners really do ask what email service you're using quite early these days, the only universally acceptable answer is self hosted (either Exchange or something else), which strikes me as crazy considering how difficult to do properly that is, but there we are.