RE: A second server as long-term archive, running eg Piler. This could also be a VM, with easily extendible storage…
I was reading the Piler documentation I found this -
" This leads to a limitation: piler will hide an email from a user if he was (only) in the Bcc: field. This limitation has another side effect related to external mailing lists. You have to maintain which user belongs to which external mailing lists, otherwise users won’t see these messages. Internal mailing lists are not a problem as long as piler can extract the membership information from openldap OR Active Directory.
Fortunately both Exchange and postfix (and probably some other MTAs, too) are able to put envelope recipients to the email, so the limitation mentioned above is solved. "
That is going to lead to issues. So I think I will give a Piler solution a miss.
RE: This server could get copies of all incoming and outgoing mails from the original server, either by using Imapsync or setting up the archive server in a mail pipeline using it as smarthost or forwarding for the real mail server.
ImapSync itself to a second server (VM?) could be a solution, depending on setup.
Would you know if Email > Connectors is used if the emails are deleted at the remote end if the local still keeps a copy? The Email > Synchronization has the option not to delete local on remote deleted emails but there auto sync “Check this accounts every” like the the Connector. Maybe a Crontab could be setup but it would be better if it could be set up with different times for different syncs.
Kind regards Mark