Since my most recent upgrade (Friday) all of my sieve filters are failing with a disconnect error generated by postfix. The particular filters are redirecting messages to other boxes on the same server. I am running dockerized.
relevant logs (sanitized):
Jan 29 02:20:31 [container_id] dovecot: lmtp([process_id]): Connect from [internal_ip]
Jan 29 02:20:31 [container_id] dovecot: lmtp([user_email])<[process_id]><[unique_id]>: Error: smtp-client: conn postfix:[port] ([ipv6_address]:[port]) [1]: connect(postfix:[port]) failed: Connection refused
Jan 29 02:20:31 [container_id] dovecot: lmtp([user_email])<[process_id]><[unique_id]>: Error: sieve: msgid=<[msgid]>: redirect action: failed to redirect message to <[redirect_email]>: smtp(postfix:[port]): RCPT TO failed: Failed to connect to remote server (temporary failure)
Jan 29 02:20:31 [container_id] dovecot: lmtp([user_email])<[process_id]><[unique_id]>: Error: sieve: Execution of script /var/vmail/sieve/[sieve_script].sieve was aborted due to temporary failure
Jan 29 02:20:31 [container_id] dovecot: lmtp([process_id]): Disconnect from [internal_ip]: Logged out (state=READY)
Jan 29 02:20:34 [container_id] dovecot: lmtp([process_id]): Connect from [internal_ip]
Jan 29 02:20:34 [container_id] dovecot: lmtp([another_user_email])<[process_id]><[unique_id]>: sieve: msgid=<[msgid]>: discard action: Marked message to be discarded if not explicitly delivered (discard action)
Jan 29 02:20:34 [container_id] dovecot: lmtp([another_user_email])<[process_id]><[unique_id]>: Error: smtp-client: conn postfix:[port] ([ipv6_address]:[port]) [1]: connect(postfix:[port]) failed: Connection refused
Jan 29 02:20:34 [container_id] dovecot: lmtp([another_user_email])<[process_id]><[unique_id]>: Error: sieve: msgid=<[msgid]>: redirect action: failed to redirect message to <[redirect_email]>: smtp(postfix:[port]): RCPT TO failed: Failed to connect to remote server (temporary failure)
Jan 29 02:20:34 [container_id] dovecot: lmtp([another_user_email])<[process_id]><[unique_id]>: Error: sieve: Execution of script dict:proxy::sieve_before;user=[user_email];name=active was aborted due to temporary failure
Upon further review it looks like this is just related to the global sieve filter, not individual box filters.