I added an automated test to our codebase that would check for BOM in SQL-files, which Windows wielding colleagues apparently were editing in Notepad. I never knew how they did it; thanks!

Yes, you can tell Motion to run a command when motions starts, when motion ends etc. I don’t use that functionality at home, but at work I use it to send an XMPP message e.g. when somebody enters the serverroom and when the video is completed (including a link to the video), so I can keep track of who enters and what they do.

I have had to fiddle a little with ignoring part of the image that constantly flickers in the server room; I can recomment Motion, it works well.

weewx does enough that I haven’t bothered doing something with the data myself - I’ve only changed the display (colours and such) to integrate it into my website.

I’ve been hosting email myself for 15+ years. Postfix made it easier to configure (Sendmail was… complicated, in comparison, in my opinion.) Dovecot works really well for IMAP/POP3. Finally Let’s Encrypt allows you to get a nice certificate relatively easily.

Greylisting helped a lot to reduce spam, but spam is still a nuisance - especially if you don’t have good filtering in your mail client (I’m using crm114).

Setting up SPF, DKIM and DMARC can be a little complicated, but it seems to work fine, as long as all email from your domain is sent from a well defined set of IPs.

I’ve not had many problems, but there’s a bit of luck of the draw in getting a clean IP. I have SPF and DKIM set up (not DMARC), with the self-signed certificate that Debian auto-generated, and that seems to be enough to get mail delivered to the big providers.

For incoming spam, I reject hosts that: 1) lack valid RDNS, or 2) are on the Spamhaus ZEN RBL. This seems to catch >95% of spam. Minor config hint if you’re using the free Spamhaus tier: you need to set up a local DNS resolver (I use unbound) so you query directly, otherwise your usage gets aggregated with whoever else is using your upstream DNS, which probably exceeds the free tier.

Like the other commenters, I use Postfix, which is reasonably nice, and has good documentation.

Mostly positive. I had that discussion this morning on IRC, so I’m gonna quote myself to not retype everything:

[...] on a "decent" hoster blacklist-wise and not DO or something
and it's been running for 10 years, I don't seem to have the typical 
"gmail thinks I am spam"-problem
usually.
interestingly I had it yesterday when sending something to myself
but dunno, empty body, 25mb-video.. who knows
I hardly use my gmail-account

But thinking about it, sending a job application in November ended up in the spam folder for 2 people and I only got a reply once I pinged them out of band. That was a shitty experience, but as I hate using GMail I prefer this to a years-long shitty experience using it :P

If I was to “start over” these days I might go to a dedicated email hoster like FastMail, but I think it’s just too expensive. I have 4 people with their main email addresses on my server and it costs me 10 EUR /month and I get to host other “communication” services as well. For FM it would be 15-20 USD per month and I still haven’t found out if I could use “a low amount of” domains and not just “use your own (one) domain”. Sure it takes some maintenance work, but it’s part hobby, part learning experience and part keeping in touch how stuff is done as it touches on my dayjob, depending on which role at what company I do. (Been running my own mailserver for roughly 15 years I guess)

Generally, problem free since I started doing it in the mid 2000s.