Mailboxes on your own domain
Mailboxes on your own domain with webmail and your mail apps. Your plan sets how many mailboxes, how much space in each and how many domains you get.
Give each person an address on your domain, such as you@example.com. Read mail in webmail or in the mail app you already use, on your computer or your phone.
- IMAP on port 993, and SMTP on 587 or 465
- JMAP over HTTPS, for the apps that use it
- 50 MB the largest message the server accepts
- 90 days between new DKIM keys, published for you
Mail Hosting on each plan
Once the account plans are open, Mail Hosting comes with every plan at no extra charge. Your plan sets how many mailboxes you get and how much room each one has. Until the account plans open, Mail Hosting is sold as plans of its own. Each plan sets how many mailboxes you get, how much room each one has and how many domains it takes.
Free
Email on one domain for a few people.
- 5 mailboxes
- 1 GB in each mailbox
- 1 mail domain
- Webmail and mail apps
Pro
More mailboxes, with more room in each.
- 10 mailboxes
- 10 GB in each mailbox
- 3 mail domains
- Everything in Free
Business
Email for a whole team.
- 50 mailboxes
- 25 GB in each mailbox
- 10 mail domains
- Shared mailboxes
- Everything in Pro
Compare every plan · Talk to sales about Enterprise
Technical specifications
How mail apps connect, what each plan holds and how your domain proves its mail is genuine.
| Protocols | |
|---|---|
| IMAP | Port 993 with SSL/TLS, or port 143 with STARTTLS |
| SMTP for mail apps | Port 587 with STARTTLS, or port 465 with SSL/TLS |
| JMAP | Over HTTPS on port 8443 |
| POP3 | Not offered |
| Automatic setup | autoconfig and autodiscover, and SRV records for IMAP, submission, JMAP and CardDAV |
| Mailboxes | |
| Mailboxes on each plan | 5 on Free, 10 on Pro and 50 on Business |
| Space in each mailbox | 1 GB on Free, 10 GB on Pro, 25 GB on Business and 50 GB on Enterprise |
| Mail domains on each plan | 1 on Free, 3 on Pro and 10 on Business |
| Storage | One pool for the service, shared out as each mailbox’s quota, 100 MB at the least |
| Region | We choose it when we set the service up, and the service’s panel shows it |
| Sending | |
| Messages an hour | Up to 200 for each mailbox, and for all the mailboxes of one domain together. Mail over the limit waits and goes out in a later hour. |
| Messages a month | No monthly cap |
| Where sent mail leaves from | Our shared sending pool, which uses a delivery partner for now |
| Authentication | |
| SPF, DKIM and DMARC | Published for you when the domain’s DNS is on Coritan |
| DKIM keys | An RSA key of 2048 bits and an Ed25519 key, both replaced every 90 days |
| DMARC | Starts at p=none, then moves to quarantine and reject |
| MTA-STS and TLS-RPT | Records that ask other mail servers to deliver to you over TLS, and to report when they cannot |
| Access and API | |
| App passwords | One for each mail app, each revoked on its own |
| Two-factor sign-in | Six-digit codes from an authenticator app |
| Client API | Domains, mailboxes, aliases and imports over HTTPS with an API token |
What Mail Hosting includes
Each feature says whether every plan includes it or which plan adds it.
Reading and sending
- Webmail. Included. Read and send mail in your browser, with labels, filters, forwarding and out-of-office replies. Webmail
- Your mail apps. Included. Use Outlook, Apple Mail, the mail app on your phone or any other app that reads mail over IMAP. Many apps fill in the server details for you. We do not offer POP3, so choose IMAP when an app asks.
Addresses
- Aliases and a catch-all. Included. Deliver mail for one address to one or more mailboxes, or catch every unknown address on a domain. A catch-all delivers to exactly one mailbox, and a domain has one.
- Shared mailboxes. Business and up. Share a mailbox such as support@ with the people who answer it, to read only or to read and send from. The other person needs a Coritan account.
- Mail from your old provider. Included. Copy mail into a mailbox from another server, from Gmail or Microsoft 365, or from a backup file. The import reads IMAP, and mbox, eml, zip and cPanel backup files.
- Extra mailboxes. Add-on. Add a mailbox to the email your plan includes, with the same space as the others.
Security and delivery
- Mailbox security. Included. Give each mail app its own app password, and turn on two-factor sign-in for a mailbox. Webmail then asks for a six-digit code from an authenticator app after the password.
- DNS records set for you. Included. When the domain’s DNS is on Coritan, we publish the records your mail needs and keep them up to date. DNS hosting
- DKIM keys that rotate. Included. We sign your mail with DKIM and replace the keys every 90 days. The old key keeps signing until your DNS has the new one.
How DMARC moves up in stages
DMARC tells receivers what to do with mail that fails its checks. We raise it one stage at a time, as your reports show your mail passes.
- Every domain starts at p=none. Receivers deliver mail that fails DMARC as usual, and send reports about it.
- The reports decide. Once a day we look at each domain. It moves up one stage after 14 days at its stage, when the reports cover at least 100 messages, 98% of them passed and no receiver sent a failure report.
- Then p=quarantine. Receivers treat mail that fails as suspicious, which often means the spam folder.
- Then p=reject. After another 14 days that pass the same way, receivers refuse mail that fails. The ramp never moves a domain down.
What customers build with Mail Hosting
Email for a small team on its own domain
Add example.com, create a mailbox for each person, and let each of them read mail in webmail or Outlook.
Uses: Mail Hosting and a domain in our DNS
One address for the whole sales team
Create an alias such as sales@ that delivers to every mailbox on the team.
Uses: Mail Hosting
Forward addresses with aliases
A move from Gmail or Microsoft 365
Sign in to the old account from the import form, and we copy its folders into the new mailbox. Then point the domain’s MX records here.
Uses: Mail Hosting and your old account
A support mailbox that several people answer
Share support@ with each person on the team, who each need a Coritan account. Each of them opens it in webmail beside their own mailbox.
Uses: Mail Hosting on the Business plan
Limits
The fixed limits of a mailbox and a domain, whatever your plan.
| Messages | |
|---|---|
| Largest message | 50 MB, attachments included |
| Largest message an import brings | 50 MB |
| Sent in an hour | Up to 200 for each mailbox, and up to 200 for all the mailboxes of one domain together |
| Sent in a month | No monthly cap |
| Mailboxes and domains | |
| Smallest mailbox quota | 100 MB |
| A domain | On one mail service at a time |
| A catch-all | One for each domain, delivering to exactly one mailbox |
| Sharing a mailbox | With people who have a Coritan account |
| POP3 | Not offered. Mail apps use IMAP or JMAP. |
Coritan runs the mail platform: mailboxes, queues, authentication (SPF, DKIM and DMARC), abuse controls and sending limits. Dedicated IP plans send directly from Coritan's own addresses. Shared sending uses a delivery partner while Coritan builds out its own shared sending pool.
Add-ons
An add-on raises one limit without a change of plan.
- Extra Mailbox: One more mailbox on the email your plan includes, with the same space as the others.
Guides for Mail Hosting
Our docs explain each step, from your domain to your first message.
- How Mail Hosting works: How domains, mailboxes and aliases fit together.
- Order Mail Hosting or SMTP Relay: Order a mail plan, or set up the email your account plan includes.
- Add a domain to Mail Hosting: Publish the domain’s DNS records and verify it, so its mailboxes can send and receive.
- Create and manage mailboxes: Create mailboxes, reset passwords and change how much space each one has.
- Connect a mail app to Mail Hosting: Set up a desktop or phone mail app, with automatic setup or the server names.
- Move existing mail into a mailbox: Bring mail from another server, from Gmail or Microsoft 365, or from a backup file.
- How webmail works: How to open webmail, and which mailboxes it shows.
Set up your mailboxes
Start on the Free plan and add your own domain.
Frequently asked questions
Does Mail Hosting cost extra?
Once the account plans are open, every plan includes Mail Hosting at no extra charge, and your plan sets how many mailboxes you get. You pay only for extra mailboxes you add. Until the plans open, Mail Hosting is sold as plans of its own, and this page lists them with their prices.
Can I use Outlook, Apple Mail or the mail app on my phone?
Any mail app that uses IMAP and SMTP works with your mailbox, and so do apps that use JMAP. Apps that support automatic setup fill in the server names for you. Otherwise read mail over IMAP on port 993 with SSL/TLS, or on port 143 with STARTTLS, and send over SMTP on port 587 with STARTTLS, or on port 465 with SSL/TLS. JMAP apps connect over HTTPS on port 8443. We do not offer POP3.
Can I read my mail in a browser?
Every mailbox opens in webmail at www.coritan.com/webmail. There you can sort mail with labels and filters, forward it, set an out-of-office reply and keep an address book. You can also share a mailbox with another Coritan account.
Can one address deliver to several people?
An alias delivers mail for one address to one or more mailboxes, so sales@ can reach everyone on your sales team. A catch-all takes mail for every unknown address on a domain, and it delivers to exactly one mailbox.
How do I move my email from another provider?
Copy it into a mailbox from another server over IMAP, from Gmail or Microsoft 365, or from an mbox, eml, zip or cPanel backup file.
How large can a message be?
The mail server accepts messages up to 50 MB. Mail apps make attachments about a third larger on the way out, so the files themselves need to add up to less. Share large files by link instead.
What do SPF, DKIM and DMARC do for my domain?
SPF lists the servers that may send for your domain, and DKIM signs each message. DMARC tells receivers what to do with mail from your domain that fails both SPF and DKIM. We replace your DKIM keys every 90 days, and move your DMARC record from p=none to p=reject in stages.
How many emails can I send, and where does the mail leave from?
Each mailbox sends up to 200 messages an hour, and the mailboxes of one domain send up to 200 an hour together. Mail over the limit waits and goes out in a later hour. There is no monthly cap. Coritan runs the mail platform: mailboxes, queues, authentication (SPF, DKIM and DMARC), abuse controls and sending limits. Shared sending uses a delivery partner while Coritan builds out its own shared sending pool.
