Splitting the credentials across two emails does add a minimal layer of security. The idea is that if someone intercepts one email, they still lack the full credentials. However, it's not a robust security practice. Email is inherently insecure for transmitting sensitive information, and it's best to use more secure methods, such as:

- **Password Managers**: Securely sharing passwords through a trusted password manager.
- **Two-Factor Authentication (2FA)**: Adding a second authentication factor to bolster security.