No. BlueMail no longer supports Proton Mail accounts.
This applies on every platform — Android, iPhone, iPad, Windows, Mac and Linux. There is no server address, port or password that will add a @proton.me or @protonmail.com address to BlueMail, so there is nothing to troubleshoot and no settings to hunt for.
Why there is no workaround
Proton Mail does not offer standard IMAP and SMTP the way other providers do. You cannot sign in to a Proton mailbox from a mail app with your normal password — Proton's own documentation states that its only route for third-party apps is Proton Mail Bridge, a separate desktop program, and that "we do not offer POP3 support".
BlueMail does not support that route. Because Proton provides no other way in, there is no alternative configuration to fall back on.
What to do instead
Use Proton's own app or webmail for your Proton mailbox.
Your other accounts are not affected. Gmail, Outlook, iCloud, Yahoo and standard IMAP/POP3 mailboxes all continue to work in BlueMail as normal — see Which Email Providers do you Support? for what is supported.
If you were previously using a Proton address in BlueMail and it has stopped working, this is the reason. Removing and re-adding the account will not bring it back — see How to Remove and Re-add an Account if you want to take the old account out of the app.
Adding a different account
Adding any other mailbox works normally: enter your email address and password and let BlueMail detect the settings. If a different provider is refusing to add, see Why Won't My Account Add? Quick Fixes for the one thing to change, or Can't Add My Account for the full checklist.
