Hi.
Maybe I didn't fully check the forum, but I did a search and got 0 results.

I came here to see if there were any tutorials for how to set up a mail server.
Last time I had one, I also had a proper domain with A- and MX-records and all that, but that was probably 15 years ago when me and a friend ran a small web hotel that never were that popular.

We did manage to get that working (mDaemon for Windows) and it was very straight forward with explainations and FAQs.
This was a long time ago, and I haven't used any mail servers since, so I'm afraid I've forgotten the most part.

Anywho, this Mercury seems very capable, and it's a bit out of my league, and I've been playing with it a bit, but I can't connect to it with my mail client, and I was hoping, as per the title, to find a simple tutorial on how to set up a functional mail server with the basics working.
I was a bit disappointed not to find that here, but as I wrote, I didn't do an extensive search for anything.

Would be nice with pictures and explanations for dialogs and such.

I am not aware of any tutorials. Did you find the manual? IIRC, it installs in the directory with the program. Look for a .pdf with a filename that starts with "man".

Beyond that, you can try searching this forum and asking specific questions here. There is also a Mercury Listserv support list. It has some subscribers that are not active here and also has searchable archives. This is the URL where you would get started: https://listserv.ua.edu/

Ok. Didn't occur to me to look locally. Found a PDF manual that I looked into a bit.
Thanks.

It's quite informative, could use a revision or two as it leaves out a few details every here & there.
I skimmed through the first part of configuring it, then tried to find anything about accounts and how to access them via POP3-clients.

I'm trying to use MS Outlook to connect to it, but it doesn't seem capable of doing so.
No matter what I try (Not SSL, not configured), I get this blaring username/password dialog, neither username or username@someaddress.domain works (sometimes that's usually what makes or brakes logins), and the SPA don't work (times out with error, neither can I find any such settings in Mercury/32) and APOP, if memory serves only work in the Pegasus Mail client
I've tried all sorts of things, and the manual don't mention much (or, I've missed it) other than the Pegasus Mail client.

Microsoft's Outlook has always been quite stupid (More so the last decade) when it comes to connecting to mail servers as they either stop supporting some protocols, or just remove some functions so it's hard to tell.

Could it be that I need the Pegasus mail client to access this?
I've never used this mail server before, and as I said, been a long time since last I used a mail server.

I have been away from Mercury for awhile so can't offer much in the way of specific help but know that an overview of what you are trying to accomplish will be needed in order for anyone to help. Mercury is capable of handling all incoming and outgoing mail for a "domain name that is properly advertised by your domain's authoritative DNS server" (quoted from the manual) but it can also serve as an aggregator, downloading mail from other mails servers and distributing it to the users configured in Mercury. Either way, the appropriate Mercury modules must be enabled and configured, along with the users who will be connecting to Mercury.

As for using it with Outlook, I don't know. We know that Mercury works with Pegasus Mail and I know of Mercury installations where Thunderbird and the Mail app on iDevices connect to it via IMAP.

I access Mercury with Thunderbird and other clients. I'm not sure how well it works as a POP3 server since most users seem to use IMAP. After installing Mercury you don't need a PDF anymore, there is a really good help function inside. David has spent a lot of time on a complete description of really all the features.

Well, a few hours ago I went over to have a look at my server (Remote desktop) and found that Mercury had crashed. I just remembered then that I had left it running.
So, opened it up and found a crap ton of spam running. I then quickly stopped the service and emptied the folders containing all the spam. Turned out that the Admin account was accessible.

This server is more trouble than it's worth, and I was mildly interested in running an SMTP-server that wouldn't give me lemon 24/7/365 (like previous smtpd in Linux Mint. Now running Windows btw) with no outcome.
So, with Mercury I was hoping to run a mail server that would allow me to oversee traffic.
At first glance it looked nice, but I don't have the energy currently to getting it running properly (POP3 which doesn't seem to work in Outlook, and I'm not installing a separate client just for that!) as I have other things to do.
Perhaps I'll dig into it a bit deeper in the future and learn how to make this a nuns bung hole so that the above won't happen.
But, for now it'll be offline.

Btw, I did also try accessing IMAP through Outlook, but still with the same result; Outlook prompting Username/Password, and Mercury don't say what the the problem is, just shows something trying to login, but that's it, so I'm putting a cork in this for now.

Thanks all for all replies & thought.

There is no problem, Mercury simple doesn't know your user. First you have to add every account manually and set a proper password. IIRC, the only difference is the administrative account with password you set up while running the installation routine.

smtpd, exchange and hmail doesn't work out of the box, first you have to setup different things.