Google Workspace, Microsoft 365, Proton or Kerio: which email for your business

Where you start: hosting email

Almost every small business starts the same way: you buy a domain, the hosting includes a few mailboxes, and email works. For years it is fine. Then the business grows and the limits arrive all at once.

• Small mailboxes that fill up, and messages bouncing back to the sender.
• Weak spam filtering, with phishing reaching inboxes and legitimate mail ending up in spam.
• No shared calendars, common address books or properly managed group mailboxes.
• Incomplete domain authentication: without SPF, DKIM and DMARC your emails land in customers' spam folders, and anyone can pretend to be you.
• No control over access: no two-factor authentication, no way to lock the phone of someone who has left.

At that point there are four routes. Two are the big American suites, Google Workspace and Microsoft 365. One is Proton, Swiss and built on encryption. The last is keeping email on a dedicated server, such as Kerio Connect, managed by whoever runs your IT.

The four routes compared

Prices are list prices in dollars with an annual commitment, excluding VAT: in euros and with monthly billing they vary slightly. For Microsoft they apply from 1 July 2026, when Business Basic rose from 6 to 7 dollars and Business Standard from 12.50 to 14, while Business Premium stayed at 22 (The Register). For Google they are the Business Starter, Standard and Plus plans (Google); for Proton, Mail Essentials, Workspace Standard and Workspace Premium (Proton).

Google Workspace

It is the simplest option to adopt. Almost everything happens in the browser, sharing documents is immediate and administration is straightforward. It suits young businesses, teams that collaborate heavily on the same files and anyone who does not depend on Office.

• Pros: an interface almost everyone already knows from Gmail; real-time collaboration on documents and sheets; very effective spam filtering; simple administration.
• Cons: people who use Excel and Word in depth feel constrained by Sheets and Docs; device management and security rules are less rich than Microsoft's on the basic plans.
• Privacy: from Business Standard you can choose to keep data at rest in Europe, email included (Google). Google remains an American company.

Microsoft 365

It is the natural choice for people who live in Outlook, Word and Excel, use Teams for meetings and need central management of users, access and devices. For groups with several sites, companies or domains it is the most complete tool.

• Pros: full, up-to-date Office; Teams and SharePoint in the same environment; very granular access rules, two-factor authentication and device management, especially with Business Premium; shared mailboxes for leavers.
• Cons: many settings, some with defaults that are too permissive, such as external file sharing; licences need careful handling: removing a licence from a mailbox without converting it deletes the mailbox after 30 days.
• Privacy: since February 2025 Microsoft has completed the EU Data Boundary, meaning it stores and processes European Microsoft 365 customers' data in Europe, with a few exceptions for security (Microsoft). It remains subject to US law, however: in June 2025, before the French Senate, Microsoft France's legal director said he could not guarantee under oath that data would never be handed to US authorities (heise).

Proton

Proton is built around privacy. Email is stored with zero-access encryption: Proton cannot read it. Between Proton addresses messages are end-to-end encrypted; to outside addresses they travel protected by TLS like other email, and you can send password-protected messages (Proton).

• Pros: the provider cannot read the content of your email; the Workspace plans also include Drive, calendar, VPN and a password manager for the whole team; prices in line with the American suites.
• Cons: subject lines are not end-to-end encrypted; to use Outlook or Thunderbird you need Proton Mail Bridge, an app installed on every computer (Proton); fewer integrations with business software and third-party tools; no Office.
• Jurisdiction: Proton is Swiss. In August 2025, because of proposed changes to Swiss surveillance law, it announced it would move most of its physical infrastructure out of Switzerland, to Germany and Norway (heise).

We recommend it to professional practices, associations and businesses that handle confidential information and do not need Office, or as a second, encrypted mailbox alongside the main suite.

Kerio Connect, managed by us

Then there is the dedicated mail server route. Kerio Connect, by GFI, provides email, calendars, contacts and phone sync, and runs on a server you choose. We manage it for businesses and professional practices that want to know exactly where their messages are.

• Pros: data lives on a server whose location and owner you know; no cloud provider in between; predictable costs that do not rise with the American suites' price lists.
• Cons: security rests entirely with whoever manages the server. Webmail and mail services are exposed to the Internet by definition and must be updated regularly: in 2025 and 2026 Kerio Connect received several security fixes, which we collected in our article on Kerio. No office suite.

That is why Kerio only makes sense if someone really looks after it. On the servers we manage we track the installed version, read GFI's bulletins, update at agreed times with backups and a service check, close ports that are not needed and enable two-factor authentication for webmail and administration.

Privacy: where data lives and who can read it

Under the GDPR all four routes can be used correctly, with a data processing agreement with the provider. The difference lies in two questions.

For anyone handling health data or highly confidential information, what is sent by email matters too: test results and patient documents should not travel as plain attachments, whatever the service. A portal or a protected link is better.

The migrations we have done

We have moved email in almost every direction: from hosting mailboxes to Google Workspace and Microsoft 365, from on-premise servers to the cloud, and from one suite to another. Three examples, without names.

1. 01

   From Google Workspace to Microsoft 365

   A healthcare group with several sites. Today email, calendars, Teams and documents shared on SharePoint live in the same environment, with a single point of access management. Leavers' mailboxes become shared mailboxes, and we are extending two-factor authentication to every site.

2. 02

   From an on-premise server to Exchange Online

   A group of laboratories had an on-premise anti-spam gateway and a Postfix relay. We moved email to Exchange Online and fixed SPF, DKIM and DMARC across 8 domains, up to DMARC p=reject (the case).

3. 03

   From hosting email to a suite

   Businesses and practices that started with the mailboxes included with their domain. Moving to Google Workspace or Microsoft 365 brings large mailboxes, serious spam filtering, shared calendars and domain authentication in order.

The method is always the same: an inventory of mailboxes, aliases, calendars and applications that send email; DNS TTL lowered a few days before; mailboxes copied in batches while email keeps arriving at the old system; MX records switched at the agreed time with a final sync; then SPF, DKIM and DMARC, Outlook and phones. We describe it in detail on the email migration page.

The most common mistake we see is forgetting who sends email without being a person: business software, scanners, printers, the website, the phone system. If they are not in the inventory, they stop working the day after the migration.

How to choose

There is no single right answer. What matters is how you already work, how much privacy and control weigh, and who will look after the system after the migration.

Need to choose or change your email?

Tell us what you use today, how many mailboxes and how many domains you have. We will tell you which route makes most sense for you and how to get there without stopping the office.

How we wrote this article

At Cloudfactory we also use artificial intelligence in our editorial work: it helps us find and cross-check sources, compare data, set up the structure and polish the language. The system we use is configured by us, with instructions, examples and procedures built around the way we write. Our team checked every source, corrected the text and approved the published version. The assessments and choices are Cloudfactory's, and we are accountable for them.

Frequently asked questions

Sources

1. Google, Google Workspace pricing
2. Google, Data covered by Data Regions
3. The Register, Microsoft 365 boosts prices in 2026
4. Microsoft, Microsoft completes landmark EU Data Boundary
5. heise, Not sovereign: Microsoft cannot guarantee the security of EU data
6. Proton, Business plans
7. Proton, How Proton Mail messages are encrypted
8. Proton, Proton Mail Bridge
9. heise, Proton relocates parts of its infrastructure from Switzerland
10. GFI, KerioConnect product releases