Skein vs Fastmail: independent email or a follow-up agent

Fastmail is a paid, independent email service known for speed, open standards and a clear privacy stance. It has chosen not to build AI into its product: instead it offers an MCP server so you can connect an AI tool of your choice when you want to. Skein takes the opposite bet: an agent built into your business email that follows up on every conversation and, by default, asks for your approval before anything is sent.

If you want email that stays out of your way, Fastmail is excellent. If you want email that makes sure the quiet thread gets a reply, that is what we are building.

Fastmail shows euro prices to visitors in Europe. Standard includes 60 GB of storage per user and Professional 150 GB. Fastmail also sells personal plans (Individual, Duo, Family) that support custom domains.

• Standards. Fastmail helped create JMAP, the modern open protocol for email, and supports IMAP, CalDAV and CardDAV properly. Any good mail or calendar app works with it.
• No AI unless you bring it. Fastmail says it has not integrated AI into the product and your mail is not piped through a model in the background. For teams that want plain email, that is a feature.
• Price. Standard at €5 per user per month on annual billing is a fair price for a quality mailbox, and cheaper per person than Skein with the agent.
• A long track record. Fastmail has run paid email for over two decades. Skein is not open yet.

The agent is the point

Skein reads every thread on your domain and notices what went quiet: the buyer waiting three days for an answer, the partner who asked for the data room, the candidate waiting on next steps. It drafts the follow-up in your tone, attaches what was asked for, and explains why it thinks a reply is due.

You approve in the app or, at launch, in Slack with a button or a reaction, or in WhatsApp, and every send has a few seconds to undo. It can send on its own only for the contacts you choose. Every action is logged with who approved it.

EU hosting for everything, from the start

Fastmail’s new EU region keeps the primary copy of your data in Amsterdam, with replicas in the US for now. Skein runs mail and agent in Frankfurt for every customer, and your mail is never used to train AI models. Our guide to GDPR and EU email hosting covers what to look for in any provider.

Meetings and a daily brief

Skein proposes meeting times from your Google, Microsoft or iCloud calendar inside the thread and sends the invite, and each morning it sends a brief of who is waiting and what the agent did. Pricing is per person with the agent, with mailbox-only seats for the rest of the team: see the pricing section.

• Pick Fastmail if you want dependable, standards-based email and calendar with no AI built in, or you prefer to connect your own AI tool on your terms.
• Pick Skein if your team loses deals, rounds or candidates to slow replies, and you want the follow-ups drafted for you and sent with your approval by default.

Weighing other privacy-minded options? Read Skein vs Proton Mail and European email providers.

Fastmail supports IMAP, so your history can be copied out with any standard tool. On supported DNS providers, Skein writes your new records for you; anywhere else, you paste four lines.

1. 1Create the mailboxes and shared addresses in Skein.
2. 2Copy your mail history over IMAP; ask about it on the setup call a founder does with each team.
3. 3Export calendars and contacts from Fastmail as files if you want to keep them.
4. 4Point MX records at the new provider, and replace Fastmail’s SPF and DKIM entries.
5. 5Keep Fastmail for a short overlap, then cancel.

Unsure about DNS? MX records explained walks through it.

Skein is not open yet. It opens to its first teams soon, in waves, and founders can reserve a spot now on the founder price. Until then you can try the demo with sample mail, nothing to install.