Say I’d like to run a small server with very little load to provide email and chat for my own personal use. Maybe three users in total.
Could I trust a Raspberry Pi to this role? I’m a bit worried it will just die on me and that I’d have to replace the unit. How durable are these things?
Running a pi here with web- and mailserver for a few users for 2 years now. No hardware problems encountered so far. The pi may actually be a bit oversized for that task...
The RPi is certainly capable of fulfilling the role you describe. The only caution I have is that a stable power supply is essential. I've had RPi servers running for weeks and months with no issues, but dropping power can result in a corrupted card. Of course, dropping power on any server is generally a bad idea, so the RPi is hardly unique in this regard. Give it the respect you'd give any server and it should be just fine.
As the other answers already suggest, the Pi is pretty much capable to serve these needs. It also also likely to survive its time (see also here). To add to the list of references: I have a remote data logging running 24/7 for almost two years now on a type B. The system's current uptime is 183 days, which is not even the Pi's fault.
However if you setup a mail server you might want to consider to not keep your mailbox solely on the SD-card but implement a backup scheme to regularly mirror it to another storage device. Rumor has it that power brown-outs may ruin SD cards on the Pi.
Same goes for the chatlogs if you have an inclination to hold on to these.
The answer turns out to be no.
I’ve had two Pis die on me, and about six medium-price tier SD-cards from SanDisk have broken down since I asked this question just 11 month ago.
