My own mail server, and it actually delivers

What it is

Roundcube is open-source webmail: the page you sign in to read and send mail from a browser. It is the visible part. The real work happens underneath, in two long-established mail programs. Postfix accepts and sends mail between servers. Dovecot stores the mailboxes and serves them to Roundcube, and to any phone or desktop mail app that connects directly.

Here those run together as docker-mailserver, a packaged setup that keeps the pieces consistent. Roundcube sits on top of it as one more client.

Why I run it instead of the SaaS alternative

For most businesses, Microsoft 365 or Google Workspace is the right home for mail. They are reliable, they handle spam well, and their sending reputation is something a small server has to earn. If you want mail to be someone else's problem, pay for it. I recommend that often.

I run my own for three reasons. I host a lot of domains, and per-mailbox pricing across all of them would be absurd for what they carry. I want the mail on a disk I control, not read by a provider's systems for any purpose. And running mail properly is the best way to understand it, which matters when a client's mail is being rejected and nobody can say why.

Self-hosted mail has a reputation for landing in spam. That reputation is mostly earned by servers set up without the authentication records receivers now insist on. Get those right, keep the server clean, and mail delivers.

How it is set up here

1. One mail server for every domain. All 39 domains are served by the same Postfix and Dovecot, so adding a domain is configuration, not a new system.
2. SPF on every sending domain. A DNS record saying which server may send mail for the domain.
3. DKIM signing. Every outgoing message is signed with a key whose public half is published in DNS, so receivers can prove the message was not altered and really came from here.
4. DMARC policy. A record telling receivers what to do with mail that fails those checks, and where to send reports.
5. Verified at the receiving end. Test messages to Gmail are checked for SPF, DKIM and DMARC all reading pass, not assumed from the configuration.
6. Webmail and lists on the same base. Roundcube for browser access, Mailman for lists, both using the same server rather than a third party.

What it replaces

• Per-mailbox hosted mail subscriptions across many domains.
• Registrar-bundled mail with unclear authentication and no control.
• Third-party webmail for domains that only need a few addresses.

What it costs to run is attention more than money: watching the queue, keeping DNS records correct when anything changes, renewing certificates, backing up the mail store, and reading the DMARC reports. Skip that and deliverability decays quietly.

What I would do for a client

Most mail work I do is not moving people onto a self-hosted server. It is fixing mail where it already is. The audit checks every domain you own, including the ones you forgot, for SPF, DKIM and DMARC; finds the services sending as you without authorisation; and explains in plain words why your invoices are landing in spam.

If self-hosting is right for you, I build it as it runs here, with monitoring and a runbook. If it is not, I make your existing provider work properly and leave you with records you understand.

Questions people ask