Email hosting explained

A customer writes to hello@yourcompany.com and presses send. Her mail app hands the message to her provider's outgoing server, which has one job: find out where mail for yourcompany.com is supposed to go. It does not know, and it has no reason to. It has to ask.

The question goes to DNS, the directory that every domain has an entry in. Your domain's entry contains an MX record, which is simply the address of your email host's servers. This is the whole trick of email on your own domain. The domain is the name, the MX record is the forwarding address, and the host is the building at the end of it. You can change the building without changing the name, which is why moving providers later is possible at all.

This is also where email hosting and web hosting part ways. The same directory entry holds a different record that points your website at a web server. The two can be with different companies, and often should be, because a mailbox bundled with a website usually shares a server and a reputation with every other site on that machine.

The message reaches your host over SMTP, the protocol that servers use to hand mail to each other. Before it is accepted, the host reads two signatures. SPF says whether the sending server was allowed to send for the customer's domain. DKIM is a cryptographic signature that proves the message was not altered on the way. A third record, DMARC, tells the host what to do when those checks fail. Your host runs the same checks on every message, filters spam and malware, and finally stores the message, encrypted, in the mailbox called hello.

When you send a reply, the process runs in reverse. Your host signs the outgoing message with your domain's DKIM key so that Gmail and Microsoft can verify it came from you. A host that leaves these records unset is the most common reason a small company's mail lands in spam.

The mailbox lives on the host's server, not on any device you own. Your phone, laptop and browser all read the same mailbox over IMAP, which is why a message read on the train is already marked read at your desk. Delete it once, it is gone everywhere. The host keeps the copy, keeps the backup, and keeps the lights on at three in the morning.

That is the service you are paying for: DNS records placed correctly, mail accepted and filtered, storage that is encrypted and backed up, outgoing mail signed so it arrives, and every device in sync. Hosts charge for it either per user, where hello@ and support@ cost as much as a person, or flat for the whole account. Entry prices in September 2026 run from $1 a user at Zoho to $7 a user at Google, or $6 a month flat for unlimited mailboxes at Faivelo, where the DNS records are placed for you at the registrar.