Configure Apple Mail (iOS) for sending from your domain

If you're forwarding mail to a Gmail inbox and want to send from your custom domain (user@yourdomain.com) using Mailcast SMTP, you’ll need to set it up a little differently to make it work.

This guide walks you through manually configuring iOS Mail to:

• Use Gmail IMAP to receive your email
• Use Mailcast SMTP to send from your custom domain

Prerequisites

Make sure you have the following before starting:

• Your domain is set up in Mailcast and forwards to Gmail
• Created an SMTP user in Mailcast on the send page
• Added SPF, DKIM and DMARC records in DNS
• 2-Step Verification is enabled on your Gmail account (without 2-Step Verification, you cannot use Gmail App Passwords)
• A Gmail App Password is created for use with IMAP - Generate one here

Setup

Step 1: Add a new mail account

1. Open Settings > Apps > Mail > Mail Accounts > Add Account
2. Tap on "choose from a list"
3. Tap Mail Account

Step 2: Enter account information

• Name: Your name (e.g. "John Doe")
• Email: user@yourdomain.com
• Password: Your Gmail App Password
• Description: What to call this account (e.g. "Custom Domain Email")

Tap Next

Step 3: Enter incoming & outgoing mail server (Gmail IMAP / Mailcast SMTP)

Incoming Mail Server

• Host Name: imap.gmail.com
• Username: Your full Gmail address (e.g. email@gmail.com)
• Password: Your Gmail App Password

Outgoing Mail Server

• Host Name: smtp.mailcast.io
• Username: The full email address of the sending user you created in Mailcast
• Password: The password that was generated when you created the user

Tap Next and wait while the account verifies.

Step 4: Final adjustments

After saving, you'll be asked what to sync. Turn Notes off unless needed.

Tap Save.

Step 5: Send a test message

1. Open the Mail app
2. Tap the compose icon
3. Ensure the From address is set to your custom domain email (e.g. user@yourdomain.com)
4. Send an email to test@mailcast.io and we’ll send you an automated reply confirming everything is working correcty.

You're done!

You're now able to send mail from your custom domain on iOS Mail using Mailcast SMTP.

Why does it have to be done this way?

Most email apps assume that you’re using the same service to send and receive email. Apple Mail connects to Gmail using OAuth, which is a good thing, but then doesn’t allow you to configure a different SMTP server for sending. If you set up your email this way, then all your emails will be sent from Gmail, not your custom domain.

Gmail’s app passwords allow us to configure iOS to correctly use separate servers for sending and receiving email.