On 9 Sep 2019, at 10:08, Francis <franc...@gmail.com> wrote: > Where should I look to diagnostic this issue?
Look at the raw stored messages. Your MTA probably has an internal ID (queuid in postfix) that should tell you if the messages are getting duped before they get to dovecot. the raw messages should have time stamps showing when they were written, so that will give you something else to check in the logs. Both you mail and dovecot logs, of course. Since these are local emails on one server, is it possible that server is sending mail to the other server that is coming back as a second copy? -- Try to realize it's all within yourself/No one else can make you change
