Hello, The redirection available in each mailbox is limited to 4 addresses by default (from dovecot default settings). This parameter could be acknowledged, the ideal would be to print the set value near the field where addresses are set, near the comment "(Separate multiple email addresses with commas)" It's even more tricky, that the sieve config file "/etc/dovecot/conf.d/90-sieve.conf" is discarded following ispconfig guide, so the value must be changed into /etc/dovecot/dovecot.conf https://www.howtoforge.com/community/threads/send-copy-to-to-7-or-more-mail-adresses-solved.71750/