istream-header-filter: Fixed header name validation to use case-insensitive comparison.
istream-header-filter: Fixed header name validation to use case-insensitive comparison.

LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot