IMAP and SMTP settings for your mail app

Incoming mail: mail.open.email, IMAP port 993 with SSL/TLS (POP3: port 995). Outgoing mail: smtp.open.email, port 465 with SSL/TLS, or port 587 with STARTTLS. The user name is your full email address. The password is an app password or the mailbox password. Enter these settings by hand.

What are the IMAP and SMTP settings?Copy Anchor Link

On every server, the user name is the full address, such as you@yourcompany.com. Use the same password on the incoming and outgoing server.

Three ports do not work, on purpose:

• 143 and 110 are closed. They would send your password unencrypted.
• 25 is where other mail servers deliver to us. It has no sign-in, so a mail app cannot send through it.

Which password do I use?Copy Anchor Link

Use an app password in mail apps. The mailbox password works there too, but it is also your webmail password.

Webmail refuses app passwords on purpose. An app password stays saved on a device and never asks for your passkey, so it must not open webmail.

Give each device its own app password. You can make one in two places:

• In the app: open the mailbox, then Passwords › New app password. The IMAP and SMTP settings come with it.
• In webmail: Settings › Security, then App passwords › Create…. It asks for your current password first.

From a terminal, use openemail credentials.

In the app, a new mailbox password is added beside the old one, and the old one keeps working until you revoke it. Changing your password in webmail replaces it. Keep at least one mailbox password: without one, nobody can sign in to webmail.

Does my mail app find the settings by itself?Copy Anchor Link

Usually not. OpenEmail does not publish the records mail apps use to look up servers. Choose the manual or "other account" option and type the settings in.

How do I set it up in Apple Mail, Outlook or Thunderbird?Copy Anchor Link

Each app has a manual setup screen. Open it, then use the table above. Menu names below were checked in November 2026.

iPhone and iPad. Go to Settings › Apps › Mail › Mail Accounts › Add Account, then Add Other Account › Mail Account. Choose IMAP, then fill in Incoming Mail Server and Outgoing Mail Server (Apple's steps). For the outgoing server, fill in the user name and password too. Without them, mail arrives but does not send.

Mail on Mac. Add the account under Mail › Settings › Accounts. To set ports yourself, select the account, open Server Settings and turn off Automatically manage connection settings (Apple's steps). For outgoing mail, use port 465 with TLS/SSL on, and fill in its user name and password.

Outlook (classic, Windows). Go to File › Add Account, then Advanced options › Let me set up my account manually, and choose IMAP (Microsoft's steps).

Thunderbird. Add a mail account and choose to configure it manually (Mozilla's steps). Set Connection Security to SSL/TLS for ports 993 and 465, or STARTTLS for 587.

IMAP or POP3?Copy Anchor Link

Choose IMAP. It keeps one mailbox in sync on every device. A message read, filed or deleted in your mail app shows the same in webmail and to code that reads the mailbox through the API.

POP3 downloads mail to one device. Many POP3 apps then delete it from the server, and it is gone from webmail and every other device. If you use POP3, turn on the app's option to leave messages on the server.

Can I use my own server names?Copy Anchor Link

Yes, on Pro. Your users can connect to names on your own domain, such as mail.yourcompany.com and smtp.yourcompany.com. Add each name in the app under your domain, create the CNAME record it shows, and run its check. If your domain has a CAA record, it must allow letsencrypt.org. The certificate is issued and renewed for you. If the app says custom hostnames are not enabled, ask us to turn them on.

It won't connect or send. What should I check?Copy Anchor Link

1. User name. The full email address, not only the part before the @.
2. Outgoing sign-in. The outgoing server has its own user name and password fields. Fill them in.
3. Server names. mail.open.email for incoming, smtp.open.email for outgoing. They are different servers.
4. Port. 993 for IMAP and 465 or 587 for SMTP, never 25.
5. Password. A revoked app password stops working within a few minutes. Make a new one and enter it in both the incoming and outgoing settings.

After 10 wrong passwords for one address from one IP address, sign-in to that address from there is blocked for 15 minutes. An old device on the same network that still holds an old password can cause this. Update the password on every device, then wait 15 minutes.

FAQCopy Anchor Link

Is port 465 or 587 better?Copy Anchor Link

Both work. Port 465 encrypts from the start (SSL/TLS). Port 587 starts plain and switches to encryption with STARTTLS before you sign in. Our settings card uses 465.

Why does my mail app keep asking for my password?Copy Anchor Link

The password it holds is wrong or no longer valid. Common causes are a typo, a revoked app password, or a mailbox password that was changed and revoked. After too many wrong tries, sign-in is also blocked for 15 minutes. Enter a current password in both the incoming and outgoing settings.

Do I need an app password?Copy Anchor Link

Use one. The mailbox password also works in mail apps, but an app password is safer. You can revoke it for one device without changing your webmail password.

Can I sign in to webmail with an app password?Copy Anchor Link

No. Webmail takes the mailbox password only.

Where do I find my IMAP settings in the app?Copy Anchor Link

Open the mailbox, then Passwords, then New app password. The IMAP and SMTP settings come with the new password.

Does it work with JMAP?Copy Anchor Link

Yes. JMAP clients connect to https://jmap.open.email with the same user name and password.

RelatedCopy Anchor Link

• Webmail: read the same mailbox in the browser.
• Add your domain: the records that make mail reach the mailbox.
• Authentication: credentials for the API.