If security or privacy for the SMS is not an issue, it would be far easier to simply use an external email provider and be done with it.
If you're trying to learn email or are simply a gluteon for punishment, then this is the way to go
I haven't looked at email in a while, but when I looked a few years ago, postfix would be the preferred server vs sendmail. Maybe things have changed, or maybe something better is available now, but assuming others don't suggest something else, or better, I would suggest you start with googling how to setup postfix as the mail server to choose/use.
1) To keep things simpler to avoid conflicts with external mail servers you would want to access, I would suggest setting your wan/lan router to allow some space for some static addresses because your (internal) mail server should be on a static address.... for example, supposing your lan is 192.168.0.xxx, and a gateway of 192.168.0.0 I would set your router to assign addresses 100...254 for dhcp, and then your mail server would sit in the static range, for example 192.168.0.5 - this is the address you would eventually set your android phone to access, meanwhile, all your dhcp stuff ends up in the mish-mash of 192.168.0.{100..254}.
2) to keep things simpler to avoid conflicts with mail servers you want to access, I would suggest using odd non-standard ports for your android mail server instead of the usual default ports. This could then firewall at your router to block in both directions for extra insurance in case you haven't configured everything ok.
3) I'd recommend setting up a fresh mageia install on the "mail server" computer. You will want to install with higher msec values (older msec was 4 or 5, newer msec is server level), and set the mageia firewall to have open ports for your non-standard imap ports when you're ready to give it a go. The higher msec security will cause havok with some programs you typically use if you were running a general laptop client, so you'll be opening-up some security settings to share the computer if this is both a server and your main computer for regular use. I suggest reading up on msec and how to customize settings.
4) readup on configuring postfix in the /etc directory for the non-standard ports so that when it starts running, it appears on these non-standard ports.
5) readup on openssh, you may need to create certificates, but hopefully not required since you're accessing 192.168.0.5 - accessing by url gets much more complicated
6) postfix won't be running as 'root', so you'll also need to ensure all the right users and user permissions are set for affected directories.
7) when you install postfix, you should be able to autorun it on bootup - check the mageia control center. When setup, it will be running a daemon.
8) setting up postfix is doable, just go one step at a time, with your main focus being security, security, security as you go from successful step to next successful step.
This by no means is complete, but hopefully points you in the right directions to go read further on where you need to go.
mailserver summary - static internal IP of 192.168.0.5, wan/lan router firewalled, use non-standard ports to avoid conflicting with other things on your network
android phone summary - connects to static 192.168.0.5, non-standard ports.
Maybe other readers have other/better suggestions.