Mailfence

Mailfence is the cheapest and gives most functional features - i.e. features you can see and use (such as a calendar and webdav). They have much better security than most mailproviders but e-mails sent in clear text are stored non encrypted. That is why they can provide pop3 and smtp without a "brige" program. They are based in Belgium that has nice privacy laws. I ve had a couple of issues but their support team was very helpful, it was solved in matter of minutes. It fits my needs and is easy to use. Totally recommend this.

I am a paying customer of Mailfence (€2.50 or €7.50 per month!) and am super impressed with the platform.

You have email, calendaring, contacts and webdav space, you can bring along your own domain (for custom email addresses - super easy to setup), import emails (I did this from Fastmail) and a ton more.

There is also IMAP, POP3, SMTP, Carddav, Caldav, ActiveSync (Exchange) support, so setting up mail, calendar and contact clients is a breeze. Hell I even got ActiveSync on my Nokia 515 (Mail for Exchange app) working first go - all of my emails, contacts and calendar are in sync on this device, other services I have tried failed at this.

On top of all of this their support is top notch. As in they reply to support tickets within the day and you can always give them a call on your good old fashioned phone (9h - 17h CET), super friendly group of people. And don't worry English speakers, being based in Belgium does not mean they have poor English skills, chances are their English is better than yours!

Annnnnd on top of all of this they are a very privacy conscious group that donate 15% of their proceeds to the EFF and the EDRi yearly.

Mailfence as a company is relatively new, but the technology behind it has been around for quite a while (since 1999) in the form of their parent company ContactOffice (https://www.contactoffice.com/). It's free to try and you can upgrade to a paid subscription at any point.

I am not a paid shill for Mailfence, just a very happy customer. I have used Gmail, Fastmail, MyKolab, plus lots more and Mailfence is easily heads and shoulders above the rest.

Requires an email to register

Very secure, no ads, and plenty of features even on a free plan. Plus, it's based in Belgium, which has very strict privacy laws, so you know your data isn't being sold.
Not only that, but the paid plans are very cheap compared to competitors like ProtonMail, and offer many useful features like Mobile Sync, Custom Domains, and more.

How does one register at Mailfence for free? I inputted my name, my preferred username and a real email address for verification but I didn't receive anything. Tried it for the 2nd time with another email address for verification, still received nothing. Checked my junk folders, nothing. Waited till tomorrow, nothing. Nicht. Nada.

Wonderful platform, absolutely no issues with them in 5 years now, been using Mailfence since 2015.
My brother who lives in Belgium recommended it to me. Under belgian law (one of the most consolidated and trustworthy in the world), so it would be extremely difficult to get data from them. You'd have to get hold of a court order in Belgium to be able to do that.
Also, outstanding customer service.
Higly recommended!

I've been a customer for a couple of weeks now, and so far I can say I'm impressed by how responsive everything is. I really like the layout / design, and from what I can tell, Mailfence sticks to their promise of providing a secure platform.
Also I really like that they communicate with their customers through different media channels like reddit and twitter (apart from their integrated support chat).
There is a free version, so there is no reason to not try it: personally, I switched from a free version to the entry plan (2,50€) and I cant say I regret it!