Recent security updates to the iCloud email system can trigger false positaves for SPAM when using default email settings in Design Manager.
The DM Cloud servers generate and send an email on your behalf, and this can cause the recipients mail system to flag the message and move into Junk or delete without notice.
Setting up SMTP Relay will connect and send emails directly through the iCloud mail system, and authenticate with a special "App Specific" password generated through Apple.
First, you will need to generate the App Specific password for your iCloud account:
How to generate an app-specific password
- Sign in to your Apple ID account page.
- In the Security section, click Generate Password below App-Specific Passwords.
- Follow the steps on your screen.
Please see Apple Support article for more information:
Once you have obtained this password, it will resemble the format "abcd-efgh-ijkl-mnop"
Next, launch Design Manager, choose File > User Settings
Enter in the following settings, including your full email and App-Specific password generated.
Test the settings, if applicable, and then choose OK. Your email should be configured.
Your iCloud account should receive a carbon copy of the message, as well as appear in the sent items folder.