Trying to track down source of duplicate messages

[Alex]

Hi,

I haven't received any responses to my duplicate messages problem. It
occurred to me that I posted my full dovecot config instead of just
the changes we've made locally. I thought it might help to follow up
with just the specific config to make it easier to identify a
potential problem.

Any ideas greatly appreciated.

# doveconf -n
# 2.3.5 (513208660): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.5 (2483b085)
# OS: Linux 4.20.11-100.fc28.x86_64 x86_64 Fedora release 28 (Twenty Eight)
mail_gid = mail
mail_home = mail/
mail_location = mbox:~/mail:INBOX=/var/spool/mail/%u
mail_max_userip_connections = 500
mail_plugins = " listescape"
mail_privileged_group = mail
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 index ihave duplicate mime foreverypart
extracttext
mbox_write_locks = fcntl
namespace inbox {
  inbox = yes
  location =
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix =
}
passdb {
  driver = pam
}
passdb {
  driver = pam
}
protocols = imap pop3
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}
service imap-login {
  inet_listener imap {
    port = 0
  }
  inet_listener imaps {
    port = 993
  }
  process_min_avail = 20
  service_count = 0
}
service pop3-login {
  inet_listener pop3 {
    port = 0
  }
  inet_listener pop3s {
    address = 192.168.1.100
    port = 995
  }
}
ssl_cert = </etc/letsencrypt/fullchain.pem
ssl_cipher_list =
ALL:!LOW:!EXP:!aNULL:!RC4::!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
ssl_prefer_server_ciphers = yes
userdb {
  driver = passwd
}
userdb {
  driver = passwd
}

On Sat, Mar 30, 2019 at 4:09 PM Alex <mysqlstudent at gmail.com> wrote:
>
> Hi,
>
> I have a fedora28 system with dovecot-2.3.5 and I'm trying to figure
> out why I'm increasingly receiving duplicate emails. The message IDs
> are exactly the same. It's always two of the same messages. I don't
> think it's ever occurred in the inbox. It doesn't happen with every
> message or seemingly in every folder.
>
> I've read about dovecot deduplicate, but of course I want to prevent
> them from being duplicated in the first place. It's also happening
> much more frequently now.
>
> Could something in my configuration cause this problem?
>
> Below is the contents of my doveconf
>