Migrating From Microsoft 365 to Proton on PeteMahon.net

Closing the Loop: What I Still Want from Proton

Fri, 01 May 2026 11:30:00 +0400

This is the last post in the series. Eleven posts in, with mail, calendar, drive, notes, the office suite, and the password story all settled, the migration is done. My setup is working. So this post is a stocktake of what’s still wrong, what would have to change for the move to be complete in the way I’d want it to be, and a closing word to Proton.

Two things, really. A family plan that actually fits a household like mine, and native Linux apps for the bits that still don’t have them. Then a thank-you, because the rest of this series has been mostly praise and the criticism in this post is a small list against a long ledger of things Proton have got right.

What Else You Get: Proton VPN and Proton Meet

Thu, 30 Apr 2026 18:00:00 +0400

Most of this series has been about migrating things off M365 and onto Proton: mail, files, notes, documents. This post is about the two pieces of Proton Unlimited that I expected to be background features when I bought the bundle, and that turned out to be central to why the migration was finishable.

Proton VPN displaced a separate service I’d been paying for separately for years; a VPN service that claimed no logs but wasn’t as publicly trusted as Proton. Proton Meet was the missing piece that let me close the door on Microsoft entirely. Both came as part of the bundle I was already paying for. If you’d asked me at the start whether either justified the move on its own, I’d have said no. A few weeks in, the answer is different.

Two Vendors, Two Keys: Keeping Passwords Outside Proton

Thu, 30 Apr 2026 09:30:00 +0400

This series has been about moving from Microsoft to Proton. One thing didn’t move, and was never going to: my password manager. Bitwarden was already in place across my household before any of this began, and it stayed where it was while the rest of my stack got rebuilt.

Proton has its own password manager, Proton Pass; on the face of it, consolidating onto it would have been the consistent move. I didn’t seriously consider it and this post is about why. It has very little to do with Pass itself and quite a lot to do with deliberately not keeping all the keys to my life under a single login.

Migrating OneNote to Joplin

Wed, 29 Apr 2026 10:00:00 +0400

Getting your notes out of OneNote

Getting data out of OneNote is the part of this migration where Microsoft makes you work for it. Unlike OneDrive - where the desktop client will happily sync the entire tree to disk on demand - OneNote has no equivalent “export everything” command. The native export options are notebook-by-notebook, section-by-section, and the formats they offer (.one proprietary, .docx, .pdf, .mht) are either useless to Joplin or lossy on the way through. The route I took was OneNote desktop on Windows exporting to .one files, then Joplin’s native OneNote import on the other side.

Replacing Microsoft Office with LibreOffice

Wed, 29 Apr 2026 09:00:00 +0400

This series isn’t about LibreOffice. It’s about reclaiming a setup that doesn’t sign me in, count my keystrokes, or shove an AI assistant into every corner. LibreOffice is the bit where the office suite stops being a subscription. No licence nags, no mandatory account, no usage telemetry, no Copilot bolted onto every menu. That’s the whole point of this shift. And it’s not a fringe move - several European governments are heading the same way for a lot of the same reasons.

Moving OneDrive Files to Proton Drive

Tue, 28 Apr 2026 03:30:00 +0400

Getting the OneDrive tree onto disk

Getting every file out of OneDrive and onto local disk is the foundation step; Proton Drive’s client needs to see real files, not placeholders to files only in the cloud. The OneDrive client allows you to set your top folders to Always keep on this device, which will pull all your files down. If you have huge local diskspace, you might select them all at once for downloading.

Migrating Multiple M365 Mailboxes to Proton with One License

Mon, 27 Apr 2026 08:00:00 +0400

If you’ve arrived here from a search engine looking specifically for the shared-mailbox question, the short version is: yes, you can migrate two M365 mailboxes onto one Proton license, and you do it by temporarily moving the license between users in M365 rather than buying a second seat anywhere. The longer version assumes you’ve already done the basic Proton setup - both custom domains added and verified, MX records pointing at Proton, your primary mailbox already imported via Easy Switch. If any of that isn’t true, the previous post covers the standard single-mailbox flow first.

Migrating Your Inbox from Microsoft 365 to Proton

Sun, 26 Apr 2026 17:00:00 +0400

This is where data actually moves. Post 3 got Proton set up on your custom domain and your DNS records trusted; this post is the cutover itself - pulling mail across from M365. If you’ve arrived here from a search engine, note that the earlier posts aren’t prerequisites if you already have Proton on a custom domain with MX records created but not yet live.

Before you start

So far, your incoming email should have started appearing in your Proton mailbox, and you should have been able to send emails from Proton as well. Let’s just double-check you have everything in place.

Proton Mail on a Custom Domain: Your Address, Aliases and Catch-all

Tue, 21 Apr 2026 17:00:00 +0400

This is part 3 of a series on moving a personal domain from Microsoft 365 to Proton. Post 1 covered the why, and post 2 moved DNS to Cloudflare. This post is the heart of the migration - getting Proton Mail working on a custom domain, understanding how Proton’s address model differs from what you’re used to, and getting your DNS records right so mail delivery is trusted.

If you’ve landed here straight from a search engine, the earlier posts aren’t prerequisites - you can follow this one standalone, provided you already control your DNS somewhere that lets you add TXT and MX records.

Migrating My DNS to Cloudflare

Tue, 21 Apr 2026 10:00:00 +0400

In the previous post I wrote about why I was leaving Microsoft 365. The first practical step was moving DNS off Microsoft’s infrastructure.

Why Cloudflare

The specific trigger was licensing: once I stopped paying for M365, there was no guarantee Microsoft would keep hosting my DNS for free. I needed a provider I trusted to keep basic DNS free long-term, and Cloudflare has a strong track record on that front.

Cloudflare has been my go-to for personal projects, going back years. Their free tier is compelling, and I was able to fashion my own dynamic DNS using their APIs to access my home lab remotely. Whilst I have since shifted my network to Tailscale, I still use Cloudflare for DNS hosting on other domains I own, CI/CD integrations, CDN, and Compute. To safely minimise the number of services I consume, Cloudflare was the natural choice for my DNS migration.

Why I Left Microsoft 365 for Proton

Tue, 21 Apr 2026 09:00:00 +0400

What was working fine

I had my tenant in Microsoft 365 for nearly 10 years. Both of my domains lived there, mahon.pro for professional usage, and petemahon.net for anything personal.

It was invaluable for keeping up with the ever-evolving beast which is M365. Or is it Office? I can’t bring myself to call it all CoPilot. Starting with office.com, then microsoft365.com and then more recently microsoft.cloud. Access to a full Exchange server, 1TB of SharePoint storage, Teams, and of course the 1TB OneDrive and 50GB mail storage. All for a measly $12.99 a month. I also managed the DNS for my domains in M365, noting that the ease of having Microsoft manage these meant for a much less manual setup when adding domains. The security of the platform alone kept me hooked and I therefore evangelised it for SMBs (as a managed service).