thunderbird-android: LOGIN fallback doesn't occur if rejected pre-continuation

Expected behavior

There should be no problem in connecting to the imap.scarlet.be server and fetch incoming mails (it works in Thunderbird and in mySecureMail). These are the required settings, from the provider, which seem just normal (provider’s info in Dutch / provider’s info in French):

Incoming e-mail (IMAP) : imap.scarlet.be Port : 993 (SSL enabled) Outgoing e-mail (SMTP) : smtp.scarlet.be Port: 465 (SSL and “server requires authentication” enabled)

Actual behavior

In K-9 Mail I’m only succesful at sending email, not receiving. The following error pops up at setup:

Setup could not finish Cannot connect to server. (Command continuation aborted: #2# [NO, AUTHENTICATE mechanism not supported, mate])

I also get the error when, afterwards, I try small variations in the settings (such as disabling ‘autodetect IMAP namespace’), in account settings > fetching mail > incoming server.

Note

I posted this issue on the community mail group as well.

Environment

K-9 Mail version: 5.207

Android version: 6.0.1

Account type (IMAP, POP3, WebDAV/Exchange): IMAP