This would be awesome if it was organized in a similar way to how Thunderbird manages multiple accounts.

I love this idea .....

As a protonmail+ user using a custom domain I shouldn't have to use a filter to have my custom domain emails show up in my main inbox. I would suggest having multiple inboxes under 1 account. What I mean is you sign in with your email and you have an inbox for name@protonmail.com, another mailbox for a@domain.tld, and another for b@domain.tld . Under each of these inboxes they can all have their own spam and archive folders and whatnot. This would be much nicer, but for some users as well who prefer a unified inbox protonmail could automatically color code the mail so it is apparent which address it was sent to. This is my biggest gripe with protonmail at the moment, but if this is implemented it would be amazing.

As you can read here: https://protonmail.com/blog/protonmail-v3-8-release-notes/ (topmost comment) there won't be any separate accounts under a PLUS subscription. You will need to buy the future professional plans, which are ridiculously expensive:

"Professional plans will be priced at $8/month per account and you can add as many accounts as you want. So for 2 people, two professional accounts would be $16. For 3-5 users, the Visionary plan is the best deal because that is fixed at $24/month." (Admin)

That's 192$/year for two separate accounts and 288$/year for three and more separate accounts. So please back this feature request: https://protonmail.uservoice.com/forums/284483-feedback/suggestions/18627634-multi-user-support-for-plus-subscription

I would also like to see the feature where i can have an email to my ContactX always be automatically sent from my alias1, my emails to my ContactY always automatically sent from my alias2

Agreed ... very desirable.

"This is why I purchased the Pro plan but it ended up with just being "aliases" which aren't the same thing :("

Same here !

Please add separate mailboxes for domains, also a option to switch mailboxes within the app would be great...

This is also important to me, and am considering moving my business elsewhere.

I wanted to open this feature request as well.

I use many email addresses under my personal domain, a personal one, a default one, one for subscriptions, one of risking to spams.

Merging all of these addresses under one inbox does not help with anything at all.

I may consider switching to another email provider just for the lack of this feature.

Separate inboxes or at least sub folders for each alias is a requirement.

This is why I purchased the Pro plan but it ended up with just being "aliases" which aren't the same thing :(

Agreed: separate sub-accounts with different logins and inboxes in the same custom domain.

I agree that it would be nice to have separate mailbox

I'm using your Proton Mail Plus with multiple addresses, which I want to use for different purposes (hobbies, billing, personal contacts, business contacts). However, all incoming mail gets dumped into the same Inbox.

Would you be able to introduce a sorting feature?

For example a toggle on the "Inbox" button for mobile app, or a right-click and pull-down menu for the web app?

This is a big one...we need it

This is a big one for me.....we need separate inboxes

All email addresses in the same mailbox is not easy when we have different e-mail for different situations (friends, family, job, hobbies, administration...)

The current system puts all emails into a single inbox folder. If one has more than one email, each email address should have its own inbox subfolder.