Connect a mail app to Mail Hosting

Any mail app that speaks IMAP and SMTP can use a Mail Hosting mailbox: it reads mail over IMAP and sends over SMTP, with the mailbox's address and password. Mail Hosting does not offer POP3. This page covers finding the server names for your service and entering them in an app.

• A mailbox and its password. See Create and manage mailboxes.
• If two-factor sign-in is on for the mailbox, an app password for the app. See Create an app password.

The server names depend on the region your service runs in, so copy them from the dashboard rather than typing them from memory.

1. In the dashboard, go to Email and open the Mail Hosting service. It opens on the Overview tab.
2. Find the Mail server addresses card. Select a name to copy it.

The Mail client setup card below it lists the same settings in the order most apps ask for them:

For an app that cannot use port 993, IMAP also answers on port 143 with STARTTLS. The Mail server addresses card also lists:

JMAP

A newer protocol for reading and sending mail over HTTPS, on port 443. Use it only in an app that asks for a JMAP server.

Webmail

The address of webmail, where the mailbox can sign in from a browser. For Coritan it is https://www.coritan.com/webmail.

MX suffix

The name your domain's MX records point under. A mail app does not need it.

Once a domain is verified, it carries autoconfig and autodiscover records and SRV records that point mail apps at the right servers. See Mail DNS records. In an app that supports automatic setup:

1. Add a new mail account.
2. Enter the mailbox's full address and its password or app password.
3. Let the app look up the settings. Check that it found the IMAP and SMTP names from the dashboard.

If the app cannot find the settings, or asks for server details, set it up by hand instead.

The labels differ between apps, but each asks for the same things.

1. Add a new mail account and choose IMAP, or the manual or advanced setup.
2. For the incoming server, enter the IMAP name, port 993 and SSL/TLS.
3. For the outgoing server, enter the SMTP name, port 587 and STARTTLS. If the app offers only SSL/TLS, use port 465.
4. For both servers, enter the mailbox's full address as the username, the mailbox's password or an app password as the password, and normal password as the authentication method.
5. Save the account.

On an iPhone, iPad or Mac, the mailbox's user can skip these steps: webmail makes a QR code that installs a profile setting up Mail and Contacts. See Set up mail apps and devices.

The app shows the mailbox's folders and mail, and can send from the address. When the app saves the mail it sends to the server, those messages also appear in the Sent folder in webmail.

The app says the username or password is wrong

Check that the username is the full address and not only the part before the @. If two-factor sign-in is on for the mailbox, the app needs an app password, because it cannot send a code. A mailbox that is turned off cannot sign in; check its Enabled switch on the Mailboxes tab.

The app warns about the server's certificate

The app is using a name under your own domain, such as imap.example.com. Enter the IMAP and SMTP names from the Mail server addresses card instead: the certificate covers those names.

The app cannot connect to the outgoing server

Port 25 is for servers passing mail to each other, and many networks block it. Use port 587 with STARTTLS, or port 465 with SSL/TLS.

The app stopped signing in after many failed attempts

After 30 failed sign-ins in an hour from one IP address, the mail server refuses that address for 24 hours. Fix the password in every app that uses the mailbox, then wait for the block to end.

A message with large attachments will not send

The mail server accepts messages up to 50 MB. Mail apps encode attachments on the way out, which makes them about a third larger, so the files themselves need to add up to less. Share large files by link instead.

A mail app stopped working after the password was reset

Every app that signs in with the mailbox's password needs the new one. Apps that use an app password keep working.

• Secure a mailbox
• Mail DNS records
• Set up mail apps and devices