Connect another mailbox (Outlook, Fastmail, iCloud, your own domain)
Send from a non-Google mailbox using an app password, test it, change the settings later, and understand which mailbox wins when Gmail is also connected.
Not on Gmail? The Custom Email tile connects any mailbox that supports sending with an app password: Outlook and Microsoft 365, Fastmail, iCloud Mail, Zoho Mail, or a mailbox on your own domain. It does everything the Gmail connection does, from your address, with no Google account involved.
If you are on Gmail, use the one-click Gmail connection instead. It is faster and does not need a password.
Before you start: make an app password
Hailo never uses your normal login password. Every provider hands out a separate app password for this.
| Provider | Where to make the app password |
|---|---|
| Outlook / Microsoft 365 | account.microsoft.com, then Security, then App passwords. Two-step verification must be on. If sign-in still fails, your admin may need to enable SMTP AUTH for the mailbox. |
| Fastmail | Settings, then Privacy & Security, then Integrations, then New app password. Choose SMTP. |
| iCloud Mail | appleid.apple.com, then Sign-In and Security, then App-Specific Passwords. |
| Zoho Mail | myaccount.zoho.com, then Security, then App Passwords. |
| Your own domain | Your mail host's security or account settings. Ask your host for the outgoing (SMTP) server name and port. |
Connect the mailbox
- Open Settings > Integrations.
- On the Custom Email tile, click Connect email →. The Connect your email page opens.
- Under Provider, pick your service. Picking one fills the server settings for you. Leave it on Custom / other for a mailbox on your own domain.
- Fill in the fields below.
- Click Verify & connect. Hailo signs in to your mail server before saving anything. If the sign-in works you return to Integrations with "Email connected" and your address. If not, the form stays filled in so you only fix the field that was wrong.
The fields
| Field | What to enter |
|---|---|
| Provider | Custom / other, Outlook / Microsoft 365, Fastmail, iCloud Mail or Zoho Mail. |
| Your email address | The address proposals, invoices and replies send from. |
| SMTP server | Your provider's outgoing mail server. Filled in when you pick a provider. |
| Port | Usually 587 or 465. Filled in when you pick a provider. |
| Security | STARTTLS or SSL/TLS. Filled in when you pick a provider. |
| Username (optional) | Leave blank to use your email address. Only needed where your host's username differs from the address. |
| App password | The app password you made above. |
The presets Hailo fills in:
| Provider | Server | Port | Security |
|---|---|---|---|
| Outlook / Microsoft 365 | smtp.office365.com | 587 | STARTTLS |
| Fastmail | smtp.fastmail.com | 465 | SSL/TLS |
| iCloud Mail | smtp.mail.me.com | 587 | STARTTLS |
| Zoho Mail | smtp.zoho.com | 465 | SSL/TLS |
You can edit any of these after picking a provider, for example a Microsoft 365 tenant with its own smart host.
The connected state
The tile reads Connected as followed by your address, and "Proposals, invoices, and auto-replies send from your address." Three actions sit under it.
| Action | What it does |
|---|---|
| Send test email → | Sends a test message to the connected address over this mailbox. |
| Reconfigure | Reopens the Connect your email page with your saved server settings. Enter the app password again and click Verify & connect to save changes. |
| Disconnect | Removes the connection. Hailo asks "Disconnect this mailbox? Sends fall back to Gmail if connected, otherwise pause." |
The Connect your email page also shows a small panel with Sends as, Server and Last used once a mailbox is connected, and its own Disconnect button.
Send a test email
- Click Send test email →.
- Hailo shows "Test email sent to" your address and asks you to check your inbox.
Disconnect the mailbox
- Click Disconnect and confirm.
- Hailo shows "Custom email disconnected. Sends now use Gmail if it's connected; otherwise they pause until you reconnect."
When Gmail is also connected
Gmail takes priority. If both tiles show Connected, everything sends through Gmail, and the Custom Email tile says "Gmail is also connected and takes priority" and tells you to disconnect it to send through this mailbox. To send from the custom mailbox, disconnect Gmail on the Gmail tile.
If it didn't work
- "Email address, server, port, and password are all required." One of the four required fields is blank. Port must be a number.
- "The server rejected that username/password. Most providers need an app-specific password here, not your normal login password." Make an app password using the table above and paste that. On Microsoft 365, also check that SMTP AUTH is enabled for the mailbox.
- "Couldn't reach" followed by the server and port. The server name or port is wrong, the security setting does not match the port (587 goes with STARTTLS, 465 with SSL/TLS), or your connection is blocking it. Pick the provider preset again and retry.
- "No custom email connected yet." You clicked the test button before a mailbox was saved.
- "Test send failed:" followed by a reason. The saved app password may have been revoked. Click Reconfigure, enter a fresh app password and verify again.
- It sends from Gmail even though this mailbox is connected. That is the priority rule above. Disconnect Gmail.