ImapSync VS shade

You see this https://imapsync.lamiral.info/ ? It's only for mails but it's a great solution.

I've had to do large email migrations before and honestly, imapsync is the way to go - https://github.com/imapsync/imapsync

Do your parents have a domain, or are they just using the provider's domain? I've set up my 1522+ to backup our mail accounts using MailPlus on the Synology, and IMAPSYC running on my lab server. But it's backup only, not archiving. That technology could be used to get to your desired state, but there's some work involved to make a secure connection from the internet to your Synology possible, sync/archive the mail, configure you parent's devices to find your device, etc.

Check out imapsync (https://imapsync.lamiral.info/) - I am using it since years and migrated tousands of mailboxes without any problems.

Check https://github.com/imapsync/imapsync

I would use https://imapsync.lamiral.info/ for email and sure there is another tool for contacts and calenders.

There are two solutions for this 1. Using a tool called imap-sync to sync all your emails (it has a great incremental sync). You can run it periodically via cron 2. Using the same or similar tool and export to a database.

If you want to sync from one IMAP server directly to another, there's also the very popular imapsync: https://github.com/imapsync/imapsync

Have a look at imapsync. Source: former web hosting sysadmin. Used this many times to move email.

In general yes I do contribute to open source, although there's not too much to contribute back to open source _yet_, so the main contribution has just filing Roundcube bugs. (The main mailserver code has diverged too much from Apache James to really be useful.)

Some of the libraries I wrote are open sourced and on my Github account, e.g. the web framework: https://github.com/ScottPeterJohnson/shade