On Sat, 27 Nov 2021 09:17:45 -0600
o1bigtenor via Dng <dng@???> wrote:

> Greetings
>
> Started way back when when I got to the web full-time using webmail.
> Haven't ever setup an email system and AIUI it is a system - - -
> there are a lot of parts that have to work together to have
> everything working well.
>
> A mentor, now deceased, recommended using Claws but even that's not
> all that's needed for an email system. So - - - I'm looking for
> recommendations on what and how to setup an email system. The why
> you're using what you are is vitally important for me (as are my
> security and privacy).
>
> Please
>
> TIA

Two questions; what do you want to do with this system and whom do you
expect to receive emails from.

I've been using sendmail for over two decades+ siunce i found the
program SMTP didn't have capacity to do filtering on incoming messages.
I've stuck with it as it core package everywhere/on debian/on devuan.
FWIw, Procmail wasnt there and didn't offer anything of benefit.YMMV.

What I've basically always used is a basic standalone basic PC.

It s easiest to get a domain and dns service for the domain, with
MX record.

I use portfowarding of 25 to the mazil-server on the router.

Recommended is a firewall on the mail-server, or perhaps a better
router firewall. My router gives priority on portforwarding over IP
blocking, hence the need for firewall on the mail-server. there is
class of spammer(growing) that door knocks and then chucks without
waiting. It isn't a major problem for me atm, but being able to block
cuts down network traffic.

To me, setup of sendmail was just changing the receiving domain in the
sendmail.mc file, which is very easy and getting the filtering rules
set. then there is a bit of tuning to catch another class of spammers
in the 'access' file.

I use zen.spamhaus.org(catches ~90%) and bl.spamcop.net(catches ~5%) to
filter all incoming mail. that is in the sendamil config file and the
block certain domains ion the sendmail access file. YMMV, but google,
gmail, hotmail, live, look, yahoo, etc jst get a "404 Send post for
whitelisting". Basically any business that allows anyone to sign up for
immediate access and send bulk spam usually gains an entry, especially
if they do not respond to spam reports.

Warning; there are block lists and there are block list. Before you
signup for using any block list, make sure you understand what type
of user/busines gets on it and there is a clear and actionable
method for getting off it. there are some people/business that pedal
block lists by scrapping other lists and then set stuff in stone.

Sendmail also has an alias which you can use widely. create an alias
entry for each and every forum/lists/shop/etc you want to RECEIVE
email from. I currently have ~950 from the years. It is so easy to just
block spam/viri/phishing/hack/etc by just #blocking/dropping the alias
entry than getting entry off list. Hint use
shortshopnameYYMM@???.

The difficulty with aiias file is you can not send mail from the
address.

I use a pop server program on the mail-server to provide user access to
receive email from the mail-server. IMO LDAP doesn't have clear concise
setup instructions and seem way over top for a simple backup system.

Which users can send & receive emails is defined on the mail-server
access files. with the addition of receive only for alias file
entry.

Mine is only a simple domain server. What I do not do, or cater for are
a multitude of users or multiple domains. YMMV.

My early work amongst other stuff, was wrangling various proprietary
GUI controlled mail servers before Linux and hence I love command line
control and sendmail.