Hi,
I currently have the following setup: user1, 2, 3 copy to distribution list team1. This is so that users 1, 2, and 3 receive the emails so they stay up-to-date as a team. The distribution list team1 contains users1, 2, 3, and 4. When user4 is absent, it copies their emails to user1. Up to this point, everyone receives emails normally when they write to any of the users. The problem arises when they send an email to user1 with a copy of user3, for example, and this email disappears. (The server deletes the original and the copies.)
Log:
2025-09-17 09:58:44,242 INFO [LmtpServer-790] [name=user1@domain.com;mid=33;ip=iplocal;] lmtp - Not delivering message with duplicate Message-ID <011001dc27e3$d1129e30$7337da90$@domainexternal.com>
2025-09-17 09:58:44,352 INFO [LmtpServer-790] [name=user4@domain.com;mid=64;ip=iplocal;] lmtp - Not delivering message with duplicate Message-ID <011001dc27e3$d1129e30$7337da90$@domainexternal.com>
2025-09-17 09:58:44,469 INFO [LmtpServer-790] [name=user2@domain.com;mid=193;ip=iplocal;] lmtp - Not delivering message with duplicate Message-ID <011001dc27e3$d1129e30$7337da90$@domainexternal.com>
2025-09-17 09:58:44,576 INFO [LmtpServer-790] [name=user3@domain.com;mid=201;ip=iplocal;] lmtp - Not delivering message with duplicate Message-ID <011001dc27e3$d1129e30$7337da90$@domainexternal.com>
Can the server validate that there should always be one email left and not delete all emails with the same ID?
A server deletes original files and their copies when storage space runs out, a backup chain breaks or becomes corrupt, or the system is restarting to free up space for a large job. A system's backup strategy, or the configured retention policy for backups, also dictates when and if files are deleted.
This looks more like a loop. I think there could be more simplified approach to achieve your desired results.