Hi i have similiar problem like here: http://www.iredmail.org/forum/topic11833-iredmail-support-vocation-respone-unknown-user.html email send : from : web123 at gmail.com to : jacka at mail.com vocation sent back from : jacka at mail.com to : srs0=hmc8=v7=gmail.com=web123 at mail.com postsrsd changing return-path from web123 at gmail.com to srs0=hmc8=v7gmail.com=web123 at mail.com this is no problem for me but sieve: Vacation's messages are always addressed to the Return-Path address it is possible some how change this ugly to header to normal? dovecot --version 2.2.29.1 (e0b76e3) # 2.2.29.1 (e0b76e3): /usr/local/etc/dovecot/dovecot.conf # Pigeonhole version 0.4.18 (29cc74d) doveconf: Warning: service auth { client_limit=125000 } is lower than required under max. load (150000) # OS: Linux 3.10.0-514.16.1.el7.x86_64 x86_64 CentOS Linux release 7.3.1611 (Core) auth_master_user_separator = * auth_mechanisms = plain login auth_worker_max_count = 60 default_client_limit = 125000 default_process_limit = 25000 dict { quotadict = mysql:/etc/dovecot/dovecot-used-quota.conf } disable_plaintext_auth = no listen = * log_path = /var/log/dovecot.log login_trusted_networks = xxx mail_fsync = never mail_gid = 2000 mail_location = maildir:/%Lh/Maildir/:INDEX=/%Lh/Maildir/ mail_max_userip_connections = 128 mail_plugins = quota zlib expire mail_uid = 2000 maildir_broken_filename_sizes = yes managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave namespace inbox { inbox = yes location mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Junk { auto = subscribe autoexpunge = 30 days special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox Trash { auto = subscribe autoexpunge = 30 days special_use = \Trash } prefix } passdb { args = /etc/dovecot/dovecot-mysql.conf driver = sql } plugin { acl = vfile acl_shared_dict = proxy::acl auth_socket_path = /var/run/dovecot/auth-master quota = dict:user::proxy::quotadict sieve = /home/sieve/%Ld/%Ln/dovecot.sieve sieve_after = /home/sieve/dovecot.sieve sieve_default = /home/sieve/dovecot.sieve sieve_dir = /home/sieve/%Ld/%Ln sieve_global_dir = /home/sieve sieve_global_path = /home/sieve/dovecot.sieve sieve_max_redirects = 25 zlib_save = gz zlib_save_level = 9 } protocols = pop3 imap sieve lmtp service auth { service_count = 0 unix_listener auth-master { group = vmail mode = 0666 user = vmail } unix_listener auth-userdb { group = vmail mode = 0660 user = vmail } } service dict { unix_listener dict { group = vmail mode = 0777 user = vmail } } service imap-login { process_min_avail = 16 service_count = 0 vsz_limit = 64 M } service imap { process_limit = 4096 } service lmtp { executable = lmtp -L inet_listener lmtp { port = 24 } user = vmail } service pop3-login { process_min_avail = 16 service_count = 0 } service quota-warning { executable = script /usr/local/bin/dovecot-quota-warning.sh unix_listener quota-warning { group = root mode = 0666 user = root } user = root } ssl_ca = </etc/ssl/ca-bundle.crt ssl_cert = </etc/ssl/xxx.crt ssl_key = # hidden, use -P to show it submission_host = xxx userdb { args = /etc/dovecot/dovecot-mysql.conf driver = sql } protocol imap { imap_client_workarounds = tb-extra-mailbox-sep mail_plugins = quota imap_quota mail_log notify zlib } protocol pop3 { mail_plugins = quota zlib expire pop3_client_workarounds = outlook-no-nuls oe-ns-eoh pop3_uidl_format = %08Xu%08Xv } protocol lmtp { info_log_path = /var/log/dovecot-lmtp.log mail_fsync = optimized mail_plugins = quota sieve zlib postmaster_address = xxx } remote xxx { mail_max_userip_connections = 51200 }