Here I explain my migration from Gandi mail after their price hike (ycombinator.com) to the Dutch Soverin (soverin.net). Since I have my own domain name, I’m not captive to any provider, so migration is possible (although requires some planning).

Migration flow ¶

1. Register with Soverin and confirmed my domain ownership by adding a TXT record.
2. Import mail using their online tool (2 accounts)
3. Update MX and TXT DNS records to receive mail (soverin.net)

3. Update MX and TXT DNS records to receive plus-addressing e-mail:

4. Update DNS records to enable DKIM.¹

5. Manually imported Notes → server-side via webmail interface in the IMAP Notes folder
6. Manually import CardDAV data → client-side using macOS Contacts.app - select all, cmd-drag to copy to new account
7. Manually import CalDAV calendar data → client-side using macOS Calendar.app - export per calendar to .ics file, then import via Roundcube web interface.
8. Manually import CalDAV reminder data → client-side using macOS Reminders.app - select all, cmd-drag to copy to new account

Issues ¶

Contacts.app does not copy all contacts (solved) ¶

Some contacts (88 out 530) were copied. After searching I found that all contacts not copied contained escaped characters (with \). This happens frequently, e.g. by creating a multi-line NOTE field (which then contains \n). I created a ticket with Soverin to address this. I don’t have a workaround.

Update: Soverin has a secondary (newer?) CalDAV/CardDAV server at caldav2.soverin.net which solves these issues for me.

To diagnose, I used the following procedure:

• Copy all contacts from old to new server in Contacts.app
• Remove new server account and add back (to clear local cache)
• Select all contacts on new server
• Switch to old server, contacts not copied are not highlighted
• Invert selection (superuser.com)
• Export all non-copied contacts as .vcf, then try to find the common denominator (e.g. find the shortest contact not copied)