dovecot submission max line length

Hi all,

After upgrading Debian Bullseye (Dovecot 2.3.13) to Bookworm (Dovcecot 2.3.19), submission-login returns an error on Kerberos authentication: "Client sent invalid command: Command line is too long".

When I initially set this up on Bullseye I have seen the same issue, but adding "imap_max_line_length = 2M" solved it.

Now with 2.3.19 kerberos authentication still works (with this setting) for imap connections but it stopped working for submission.

Is there a new config setting for submission-login that I missed?  Or is this a bug in 2.3.19?

• Kees.