Does Dovecot make Foxmail / Thunderbird / Outlook to receive duplicated email?
I’ve built a
Postfix(2.10.1-7.el7.x64.rpm) + Dovecot(2.3.11-build) mail server for my host. It functions well for me at the very beginning.
After using for a while, I kept receiving duplicated mails from my server. I try to figure it out where did they come from. But I finally found they share the same
MESSAGE-ID, which is identified by receiving mails. I try to use different email client, Foxmail/Thunderbird/Outlook, but it results the same.
I try to figout it out how they functioned. And I found out when I receiving a mail, which comes from a persistent connection, it would be very easily to duplicate a mail if I pulled it from mail server by my own at the same time.
This does not make sense, does anybody knows how to config the dovecot server to avoid the duplication of mails from client? It would be great helpful for me. Thanks.