I do not think this will ever be done, bc it implies all other accounts would need to have same level of security as proton mail has.

Only way to have only one desktop app to manage all email accounts is by using something like thunderbird and add all accounts there, using bridge to connect to proton mail.

Given outlook does not allow to directly connect or add a proton mail account. This also means you need to be a paying customer to do so.

Hello Proton!
I would like to request the ability to add external email clients to Proton Mail via IMAP/POP and send and receive emails through the Proton Mail inbox.
Yes, our emails all end in proton.me, pm.me, protonmail.com or protonmail.ch. However, some people's workspaces are still reliant on Office 365/Google Workspace, and so if this could be implemented it would be real good privacy.
Thank you!

P.S Love the work you're doing. Keep it up.

I need to access emails for my Zen Internet addresses

I joined proton because of the security.
I might leave again due to missing functionality, for me this is a showstopper.

Subfeature of https://protonmail.uservoice.com/forums/284483-proton-mail/suggestions/40256476-send-e-mails-from-other-e-mail-services-via-smtp-i ?

While integration of Proton Mail into Outlook is possible, it's clunky. Making the Proton apps (Mail, Calendar) capable of acting as clients for O365 or GSuite so I can consolidate to a single app for email or calendar (and see all my calendars in one place).

The thing stopping me moving more wholeheartedly to Proton is the lack of consolidate support for Exchange/MS365/O365

To the persons who say adding this _optional_ feature that users can configure _if they choose to_ would break the security... how? If you simply don't add any SMTP configurations to send as from within your Proton mailbox, you haven't lost anything. And the users who do chose to do so, can still send Proton-to-Proton by simply not selecting the SMTP config in the send a field. Nobody loses any security that wasn't there choice to lose. If I send a message from Proton to an external mailbox, it's going to use SMTP to deliver it. So why not let me setup my external SMTP mailbox to send through directly from Proton, so that I can have all my mailboxes aggregated in my nice secure Proton mailbox?

I would also love to have this feature. Mainly because I do not want to switch between mail apps all the time.
I know that this is a security risk, but maybe it would be possible to mark the mails coming from external providers. Maybe make the whole entry red in the webmail to show the user, that this is an insecure communication.

That would break much of the security and privacy provided/obtained. So hard pass.

For the likes of Gmail, outlook, etc it is best to use a separate app.

There is no security for gmail as it resides and transits on Google's servers.

You can use PGP with GMail et al to get some privacy and security back. Things like Mailvelope or GPGTools work, though a little more manual work required.

The free Mailvelope browser extension can be used to add PGP encryption and digital signing (certified email) to Gmail, Outook.com, and Yahoo web mail.