
How to choose the best Email Client?
Welcome to the hell of my life.
Yes, I am not completely satisfied with all the current existing Email Clients.
Each time I finish selecting one app instead of another, I always have to renounce to some tools/functionings, because all the apps have always some lacks.
It appears that a truly complete program is impossible to realize.
So, periodically, I struggle again and try to test all the current options available.
Well. This time, as a reminder for the future myself, but also to help all of you to decide, I am writing this post with all the lacks. If you choose, you have to be aware.
LATEST UPDATE: 12 APRIL 2020
Mail (Windows Systems)

PROS: The cutest app
It is a very nice app, really. Very appealing, more than professional tools. And enough personalizable.
CONS: The most basic of ever
It is very basic – so highly suggested for un-professional uses, Many functions are missing. You can’t move emails from an inbox to another, you can’t create rules. Contacts are poorly organized, without the possibility to divide them into groups.
Gmail

PROS: The heaven of compatibility
Ready to use, no installation, available in any device, nice themes, high personalization, a lot of tools/plugins easy to add, and of course, extremely connected with all other google services (google calendar, google Contacts and so on). The heaven of compatibility. For many years, it became my personal client.
CONS: It always remains a website
It always remains a website, as far as you can consider it as an app – even with all the plugins and offline tools. Having everything on Google, will occupy space on your 15gb free plan.
Some competitors (as Yahoo) have made life difficult for Google-users. Indeed, their emails were not anymore compatible with the Google web client, but at the same time, many Yahoo services required a Yahoo mail. Result? You needed a new email-client or you had to manage your emails on two different websites. I don’t know if things are still like this, but you can’t count on Google forever for sure.
Outlook

PROS: Many hidden tools that you will never finish to learn
On paper, it is the most professional software available. It seems ALMOST complete, since it looses on very poor and simple battles.
CONS: On the most basic needs, it sucks
Incredibly, very basic features, that even the most rudimental apps have, Outlook doesn’t have them. Just to let you insane, I am sure of it. For example, it is impossible to have all un-read messages of all accounts, or reading all inboxes all together – you have always to click on the single inbox account. To solve this, you have to create Macros, write rules, search with parameters as Ubuntu users do on their Terminal. Are you serious??
Themes and aesthetics are sad; the app frequently slows the system or crashes.
Em Clients

PROS: One of the most complete and nice at the same time
Probably it has not all the functions available on Outlook, but it is very close to it. Also, from an aesthetic point of view, it is slightly better. Very close to perfection.
CONS: not immediate sometimes + orange madness
Compatibility seems to be assured, but sometimes that could be some issues to fix. Each time, I register on the forum, and I request help to the support.
The brand-orange choice is too much imposed, it is almost impossible to change it, and even in the forum, people complain that the website is almost unreadable.
Thunderbird

PROS: One of the most complete nr.2
As I remember, (I suddenly uninstalled it, once I discovered that graphic had never changed in all of these years), it is one of the most complete in terms of functions.
CONS: Ugly, the worst aesthetic that never changes
The titles speaks itself. Too many icons, too confusing and too retro. My eyes are hurts.
Anyway. As I remember, the compatibility (with G. Calendar and Google Contacts) was never so perfect.
Mailbird

PROS: High Compatibility + Awesome aesthetic
The aesthetic is awesome, not only very very nice but also extremely personalizable. PERFECT.
The compatibility with Google is great, with two clicks, I had without problems all of my contacts and my calendars with all my registered info.
CONS: only 1 account in the freeware versions, basic utilities missing
Having only 1 account in the freeware version is too less. There are a lot of functions dedicated to socials, instead of focusing on other basic tools: what if I would like to order emails by title? What if I want more columns with specifications on emails or accounts? Not possible. It is possible to read the account all together (great) but you can’t move a mail from inbox A, directly to a folder of inbox B. It creates a copy before. Why??
My final thoughts
For the use of a single account OR for your mother and your dad: MAIL
Young students, with no fixed office/home: GMAIL
Freelance, autonomous workers: Mailbird, eM Client
Small Teams: Thunderbird, Outlook, eM Client
My personal choice? eM Client.