How Mail Hosting works

A Mail Hosting service gives people mailboxes on your own domain. They read and send mail in a mail app over IMAP and SMTP, over JMAP, or in webmail. You manage everything from the service's panel in the dashboard: go to Email and open the service.

Domains

The names your addresses end in, such as example.com. You add a domain, prove you own it and publish its DNS records. See Add a domain to Mail Hosting.

Mailboxes

Addresses that store mail and can sign in, such as alex@example.com. Each has its own password and storage quota. See Create and manage mailboxes.

Aliases

Extra addresses that deliver to one or more mailboxes on the service, including a catch-all for a whole domain. See Forward addresses with aliases.

A mailbox or alias can only use a domain on the same service, and the dashboard offers only domains that are verified. Each domain can be on one mail service at a time.

The plan sets how many mailboxes and domains the service may hold, and how much storage it has. The storage is one pool for the whole service: the number of mailboxes multiplied by the storage per mailbox that the plan lists.

Each mailbox takes a share of that pool as its quota. A new mailbox gets an equal share by default, and you can give one mailbox more and another less, as long as the quotas together fit in the pool. The smallest quota is 100 MB.

Aliases do not count against the plan. To get more mailboxes, domains or storage, see Move to a bigger or smaller plan.

In the dashboard, go to Email, open the service, then the Overview tab.

The four figures at the top show Storage, Mailboxes and Domains used against the plan, and the number of Aliases.

Mail server addresses

The names to enter in a mail app: SMTP (ports 587 with STARTTLS and 465 with TLS), IMAP (port 993 with TLS) and JMAP (port 443). It also shows the Webmail address and the MX suffix, which ends the mx1, mx2 names your domains' MX records point to.

Mail client setup

The settings a mail app asks for, in the order it asks. See Connect a mail app.

Recent activity

The latest delivery events from the last seven days, such as delivered, bounced or deferred messages.

Service

The service's Status, Plan, Region, the date it Renews, when it was Created and its Service ID. When we pause the service's sending, the status reads Sending paused.

Tags

Labels you add to find the service. See Tags.

Domains

Each domain and its verification status. Select one to open its DNS records.

The panel header has Open webmail, which opens the webmail address in a new tab, and Order another, which opens the Mail Hosting order page for a second service.

A mailbox sends through the service's SMTP server after it signs in. The rules that apply to every mail service apply to it too:

• The From address must be on a domain of the service that has passed its ownership check.
• A recipient on the service's suppression list is refused with Recipient … is suppressed after a bounce or complaint. Bounces and spam complaints add addresses to it.
• The service has an hourly sending limit, rate_per_hour in the service summary. Mail over it waits in the queue and goes out in a later hour.
• We watch each service's bounce and complaint rates. When they cross the pause threshold, we pause the service and the panel shows Sending is paused. Until our staff lift the pause, its mailboxes cannot sign in, send or receive mail. See Sending reputation and deliverability.

To send mail from an application rather than a person, use SMTP Relay.

When you cancel the service and it ends, we delete its mailboxes, aliases and stored mail. Move anything you want to keep first.

Read the service summary:

curl https://api.coritan.com/api/v1/client/mail/4812 \
  -H "Authorization: Bearer $CORITAN_TOKEN"

The fields you need most:

kind

hosting for Mail Hosting.

status

active once the service is ready.

quota_mailboxes, quota_domains, quota_storage_bytes

What the plan allows. quota_storage_bytes is the whole pool.

counts

How many of each thing the service holds: mailbox, alias, group and domains.

used_bytes

The storage the mailboxes use.

rate_per_hour

The service's hourly sending limit.

hostnames

smtp_host, imap_host and jmap_host for mail apps, webmail_url, and mx_hostname_base, the MX suffix.

cluster.region, cluster.region_name

The region the service runs in: its code, and its name, such as Frankfurt, or null when we have no name for it.

sending_frozen, review_flag, reputation_note

Whether sending is paused or under review, and why.

service

The service's id, status and hostname.

A service that is still being set up answers 409 with This mail service is still provisioning.