Can anyone recommend me a good and secure email server to use on linux?

Dovecot

@FrodoSwaggins and @Linux would know best

I'm using iRedMail on my mailers, it's a pretty good package of all the common components in mailing systems. Makes the process of deploying it much less insanity-inducing too. Highly recommended!

I use mailcow (mailcow.email), works very well with little to no maintanance.

@FrodoSwaggins

Yes and no.

It is a suite, it includes everything to have a emailserver up and running. Problably something OP is asking about

@FrodoSwaggins

iRedmail consist of Postfix, Dovecot, Amavisd+Spamassassin+Clamav, sogo/roundcube, mlmmj + more

Any commercial email provider has some. And to make it perfect: they are maintained by professionals.

So my advice for anyone whose not an email provider or doing it for research or educational purposes: Let others deal with this internet front line!

@lastNick

I have seen so many missconfigured mailservers that was supposed to be taken care of by professional. Yes I am looking at you Microsoft.

@Linux Microsoft: “let’s just block every ISP’s IPs randomly sometimes, not explain them why but still have their customers blame them!”

Customer: *switches to Office 365*

@xalys

and also "let's add DANE to our services but dont update the records when we change the TLS-certificate"

@lastNick Most of the time I'd say this too to general users, but for people who are looking into self-hosting their mailing systems, as @RantSomeWhere mentioned, they usually have a good reason for it. For me it was a rather stupid one, having my own domain, but also controlling my mail. And it was, without even thinking about it twice - absolutely worth it. I wouldn't take it any other way.

@RantSomeWhere Awesome! For educational purposes I'd definitely recommend looking at more simple servers though, mail servers are among the hardest servers out there to deploy and maintain (hence why even experienced sysadmins tend to shy away from raw Postfix/Dovecot/SpamAssassin/yadayada). I can only assume your experience with servers to be currently zero, at which point I'd recommend testing locally with SSH. Maybe if you're more experienced with that, internet-facing.. and maybe a webserver and a VPN server or something like that. Mail servers are not without good reason called insanity-inducing though.. if you're not familiar with servers, even the likes of iRedMail can be daunting.

That being said, for those who are a bit experienced with servers, maintaining your own mail servers does give quite a lot of liberty! For example, I've grown quite fond of the ability to use my catch-all domain to make up mailboxes on the fly. This was quite useful back when I went shopping on Black Friday and some MasterCard wanketeering booth wanted a mail address to send some free picture to. mastercard@mydomain of course, but that's not one that's explicitly registered on my domain! Extremely useful to have. And unlike MS Exchange, unlimited at no more cost than that of the servers and the domain :)

@Condor I bought a domain with some web space and email hosting is included in this package. So I manage my own email addresses using my domain and catchall but the email server is hosted by the company I bought the domain from.

@lastNick you're trusting your email on the guys that host your email. Has its pros and cons. Personally I wouldn't do it...

@Condor I don’t use email for confidential stuff. 😜

@lastNick

So what do you use?

@Linux I use email for all the normal correspondence. Confidential stuff is shared over a dedicated NextCloud server. The credentials for the user accounts are handed out on paper.