Hey all, seems like a small oversight made it into 2.50. I think this bug happened a few releases ago, too: an external account is erroneously detected as chatmail.
I’m still using fastmail as my backend. The recent update caused deltachat to start notifying for all incoming emails, rather than my previous configuration of approved contacts.
Those settings are missing from the settings menu now too, so I cannot correct the situation. I cannot set “only approved contacts” nor “only check deltachat folder for messages”.
thanks and keep up the good work 
Actually the problem is somewhat worse than I initially thought.
The deltachat folder is not being checked at all, so I am receiving all mail except deltachat mail in this release. 
“Legacy options” are removed on purpose in 2.50+, this is why they have been moved to legacy options before. You should have got a device message about “move to Delta Chat folder” with a link to Use a Dedicated Chat Profile - Delta Chat in previous releases.
There are four options that have been removed or replaced:
- “Move to Delta Chat folder”. This is a breaking change and requires user action to use a separate mailbox, see Use a Dedicated Chat Profile - Delta Chat You can also create a separate mailbox on any server and configure it with
dclogin URL or QR code as described in How to migrate your profile to another relay (version 2.33) if you don’t want to use chatmail, but you need a separate inbox in any case.
- “Only fetch from Delta Chat folder” is automatically migrated into “IMAP folder” setting of the relay. It is not displayed in 2.50, but in 2.51 will be visible in relay settings if set. There is a bug in the migration in 2.50, but it will be fixed in 2.51. 2.50 is a testing release, not in the stores. If you use this setting, wait for 2.51.
- “Delete messages from the server after …”, third legacy option that is removed. In 2.51 the logic will be to remove encrypted messages automatically in single-device mode and not remove in multi-device mode. For chatmail all messages are expected to be encrypted, so in single-device mode all messages are removed. “Disappearing messages” and manual deletion also delete messages from the server.
- “Only approved contacts” is removed, but a new similar “Enforce Encryption for All Relays” setting is added to relay settings. It is not a exact replacement, but enabling it means you will not get unencrypted messages. For new users “Enforce Encryption for All Relays” is enabled, for old users it is disabled if there have been recently active unencrypted chats and otherwise it is enabled.
See also Setting up relays means getting spam? [option to block unencrypted messages]
I don’t quite understand. So, I read all the above. As I realized, I need to rename the “DeltaChat” folder to “IMAP”, but it doesn’t work either. Theoretically, I should be able to receive both encrypted and unencrypted messages there, and Delta Chat should be available not only in the Inbox but also in other folders as in previous versions.
If you used “Only fetch from Delta Chat folder” before upgrade, then Delta Chat will only fetch from Delta Chat folder and nothing else after upgrade.
If you did not use “Only fetch from Delta Chat folder” before upgrade, then Delta Chat will only fetch from the Inbox after upgrade.