Hi Guido,
Should be possible:
'app.mail.accounts.default' => [
'email' => '%USERID%@yourdomain.at'',
'imapHost' => 'imap.yourserver.com',
'imapPort' => 993,
'imapUser' => '%USERID%@yourdomain.at',
'imapSslMode' => 'ssl',
'smtpHost' => 'smtp.yourserver.com',
'smtpPort' => 486,
'smtpUser' => '%USERID%@yourdomain.at'',
'smtpSslMode' => 'none',
],
Reference: https://github.com/nextcloud/mail/pull/28