Android email client that supports traditional and encrypted (Protonmail, Tutanota) email services

Question

I use many email service providers. However cannot find any email apps that can handle all of them. Lemme explain the details:

• Email providers that support simple IMAP/POP3 like gmail, outlook, yahoo are easily accessible via any email client so I currently use BlueMail app for them which is reliable, feature-rich and supports multiple accounts.
• For some encrypted mail services like protonmail, IMAP/POP3 ain't supported on the name of security and encryption. However they have their own encrypted clients which support no email accounts except for theirs. so I use theirs for some accounts.
• Some encrypted mail services like tutanota don't even have their own client. I've to access my mails via browser in those cases.
• There are some garbage apps on playstore which claims to support all email providers yet none of them actually. Most of them are simply webapps that often crashes, forgets my credentials for some providers and do not support offline biewing of mails. There are even worse apps which simply list down all email providers and that's it.

So what do I want?

A single place on my phone for all my emails

I'm tired of switching apps just for checking mails. My phone runs Nougat 7.0 if it helps!

Answer 1

I am currently using Aqua Mail on my Android phones.

I used to stick to my phone's built-in app and found its email provider support, as well as syncing functionalities sucks, so I looked for another mail app. With my previous in MobiSystems' OfficeSuite, I decided to give their mail app a try, and found it satisfactory. They claim that this app is highly customizable, and their claim is mostly true.

I particularly like these functions:

1. Their Smart Folder, also customizable, provides a mixed view from all my accounts at once, so I can quickly find out what I have missed.

2. The synching is also flexible. I set it to 15 minutes (and add the app to Battery Optimization whitelist in my phone Settings) so I can stay up to date with my mails.

3. Colors! I have different colors for different accounts, so with a glance I can immediately know which account the mail is in.

Two potential downsides that I'd like to note:

1. The free version is somewhat limited, with only 2 mail accounts and a few ads, and the Pro key sells at US$9.99, which could be a bit expensive. But I have previously seen it sold at US$4.99 during black Friday of 2018. Alternatively, the pro key APK can be easily found on the internet, rendering the pro version practically free and gratis and it's fully functional. (Disclaimer: I didn't buy it on Google Play)

2. I do not have any encrypted mail providers, so I cannot check if this app supports them (e.g. Tutanota as you mentioned). Except for that, it works great for me.