What I miss in the book (and also on the YouTube channel AFAIK) are instructions on how to install a mail server. Jay, would you consider doing a (preferably detailed) tutorial on installing a complete mail server (Postfix, Dovecot, Roundcube, SSL) on Ubuntu server 20.04LTS? I’m sure I’m not the only one who would appreciate that!
Though no expert in Linux, coming from a more Windows networking and server environment, I have played around with Linux since the 90’s. (Suse, Slackware, and later CENTOS and much later Ubuntu.) I have installed and run both Windows and Linux mail servers at different times thoug the latter in mainly tests environment. On the Linux side the two that I used were Qmail and Postfix. (We’re talking about ten years or so ago so things may have changed.) Of the two the easiest to install and configure was Postfix. (From what I read Sendmail was horrific so never really tried it. I don’t recall trying Exim another well thought of mail server, but I may have done and forgotten. I know that I looked at it.) I got all my information from books, and I have loads of them, but these days, besides what Jay maybe able to offer, I am sure that there are lots of articles, videos, etc on the Internet. The biggest thing, unless using just for testing, is to lock down and make sure that security is tight. And also make sure, if not for testing, that DMARC is set up correctly to ensure that the mail is accepted by other systems, and you only accept mail that has been setup correctly. The bits of DMARC that you will be concerned with is DKIM, SPF. And if you are going to pass through or use other servers as well make sure those are included in your DMARC as well.
BTW I was only interested in POP3 and IMAP, and tend to only use them whereas these days many people only use webmail and have no idea how to setup and use POP3 or IMAP. QMAIL and Postfix do not include a webmail access client however there are lots of articles on the Internet how to overcome this with other apps. I know that Roundcube has been used that I believe comes with Ubuntu server, however there are other options.
I would like to know how different is to implement a mail server on linux today, after all, there are many services in the cloud that saves all the hassle to admins, but personally I find that managing your mail server gives you a lot of control. The downside always is to keep track of spam, blacklists, etc. My mail server of choice is postfix and as complements I would use spam assassin, dovecot, saslauthd, and roundcube for a web interface on a CentOS system. Those I used many years ago, so what is new today?.
I have just noticed this. As you say running your own mail server does give you complete control and you can tailor to meet your own requirements that is not always possible when you outsource. Even if you decide to run yourself that can be on your own local server or elsewhere. Locally means that you are responsible for hardware and normally keeping it on-line 24/7/12 so it can often make sense to host on a virtual server somewhere even if it costs you money and the bandwidth is likely to be better. Make sure that it is a credible virtual server hosting company as if not there can be issues even with sending mail if one of their IP addresses or part of the route they take get blacklisted. (I’ve seen this with even big players.) However you are responsible for the security, anti-spam, etc though there are better tools these days but as we all know these are not all full proof. The biggest security issue with e-mail are the users.
Outsourcing take a lot of this load over. However read the small print as there are different levels of security,etc, and if end to end encryption is offered this frequently only refers to those on the same system. Two users on joebloggs.co will be encrypted but another user being on janebloggs.co may not be unless they use the same mail hosting company. Of course a lot of this will vary depending on whether Webmail, IMAP. or POP3 is used. For my personal mail I still use IMAP and POP3 due to the greater control and flexibility it gives to me locally and though Webmail is in theory the same as IMAP you are under the control of what is provided by the mail server administration. With IMAP, POP3, and Webmail you can have secure login and transaction between the server and the clients and that is something that I think should be enforced though there is still traffic going across the Internet that can be viewed by anybody in the promiscuous mode.