Custom from requires smtpMsa configuration error.

If the user's account is created less than 24 hours ago, it might still be subject to certain restrictions, including limitations on creating "sendAs" aliases. Google applies some restrictions on new accounts to prevent potential abuse or spamming. In such cases, the error "Custom from requires smtpMsa configuration" might be thrown when attempting to create a "sendAs" alias for a newly created user. This is because the user's account may not have fully propagated across all systems and services within Google's infrastructure, including the SMTP relay service. To resolve this issue, you should wait for at least 24 hours after creating the user's account before attempting to create the "sendAs" alias. During this time, Google's systems will have had a chance to fully process and provision the account, making it eligible for creating the custom "sendAs" alias.

Updated on: 30/04/2025