When your Apple Mail app (on iPhone, iPad, or Mac) displays “Email Address Rejected by Server”, it means your device could not authenticate (log in) to the outgoing mail server (SMTP). This prevents emails from sending or completing the connection.
Without proper authentication, the mail server won’t let you send mail, which usually points to incorrect settings, password mismatches, or security requirements that aren’t met.
This guide will show you why this happens, how to fix it step-by-step, what to do if basic steps fail, and provide you with best practices to avoid it in future.
- Why This Error Occurs
- How to Fix the “Email Address Rejected by Server” Error
- Summary
- Our Scope of Support
- FAQs
- Additional Resources
- Need Additional Support?
Why This Error Occurs
This error generally arises when your device fails to authenticate with the SMTP (outgoing) mail server, causing your Apple device to be unable to send or receive emails. This error is commonly seen in iOS Mail, iPadOS Mail, and macOS Mail apps when using IMAP, SMTP, or POP email accounts.
Common causes include:
- Incorrect email settings
- Wrong server host, username, or password.
- SMTP authentication not enabled
- Required but turned off.
- Wrong port or encryption settings
- SSL/TLS mismatch.
- Password recently changed
- Device not updated.
- Email provider is blocking access
- Unrecognised device/IP.
- Temporary server issues
- Server downtime.
How to Fix the “Email Address Rejected by Server” Error
1. Restart Your Device & Check Your Internet
Temporary glitches and unstable connections can trigger errors.
Before making any changes, restart your iPhone, iPad, or Mac and ensure you have a stable internet connection.
Steps
- Close the Mail app completely.
- Restart your device (Power off and then turn it back on).
- Reconnect to a stable Wi-Fi or mobile network.
TIP: Sometimes a fresh connection clears out cached errors and allows Mail to reconnect securely.
2. Verify Your Email Login Details
If the username or password on your device doesn’t match the server’s records, authentication fails.
This means you need to ensure that your email address and password are correct, especially if you recently changed your email password.
Steps
- Go to Settings > Mail > Accounts.
- Select the affected email account.
- Tap Account Settings and verify the email address and password.
- If the password is incorrect, update it with the correct one.
TIP: It ensures your device actually has the correct credentials your mail server expects.
3. Enable SMTP Authentication
Some servers require a separate “spa” check before sending mail.
This is where authentication is required for outgoing emails, so ensure that this setting is enabled.
iPhone/iPad
- Go to Settings > Mail > Accounts.
- Select your email account and tap SMTP under Outgoing Mail Server.
- Tap the primary SMTP server (e.g.,
mail.example.com). - Ensure that Use Authentication is enabled and enter your email credentials if required.
Mac Mail
- Open Mail > Preferences.
- Select Accounts and choose your email account.
- Click on Server Settings.
- Ensure that Outgoing Mail Server (SMTP) Authentication is enabled.
TIP: This tells your mail server, “I’m allowed to send mail,” which stops rejection.
4. Check SMTP Server & Port Settings
Using incorrect SMTP settings can cause email rejection errors. Make sure your settings match your provider’s recommendations.
| Setting | Recommended Value |
| SMTP Server | mail.yourdomain.com (or as provided) |
| Port (SSL) | 465 |
| Port (TLS) | 587 |
| Authentication | Required |
| Username | Your full email |
| Password | Your email password |
iPhone/iPad
- Go to Settings > Mail > Accounts.
- Select your email account and tap SMTP.
- Tap the primary SMTP server and verify:
- Server: ON
- Hostname:
mail.example.com - Username: Your full email address
- Password: Correct password
- SSL: Enabled
- Port:
465(for SSL) or587(for TLS)
Mac Mail
- Open Mail > Preferences > Accounts.
- Select your email account and go to Server Settings.
- Verify the outgoing mail server details and ensure SSL is enabled.
TIP: Matching what the server expects eliminates most authentication mismatches.
5. Remove & Re-Add the Email Account
At times, re-adding the email account is needed if the settings are correct, but the error still occurs.
iPhone/iPad
- Go to Settings > Mail > Accounts.
- Select the affected account and tap Delete Account.
- Restart your device and go back to Settings > Mail > Add Account.
- Re-enter your email credentials and configure the account.
Mac Mail
- Open Mail > Preferences > Accounts.
- Select the affected email account and click Remove (-).
- Restart your Mac and re-add the account.
TIP: This resets any hidden configuration issues that can’t be seen in menus.
6. Update Your iOS, iPadOS, or macOS Apple Software
Outdated OS versions sometimes conflict with modern server authentication.
Ensure that your device is running the latest software update to prevent compatibility issues.
iPhone/iPad
- Go to Settings > General > Software Update.
- If an update is available, install it.
- Restart your device and check if the issue is resolved.
macOS
- Go to Settings > General > Software Update.
- If an update is available, install it.
- Restart your device and check if the issue is resolved
TIP: This ensures compatibility with current mail encryption standards.
7. Contact Your Email Provider (If Needed)
If none of the above works, your mail host may be blocking access due to security policies or unusual logins.
NOTE: Your provider can verify server logs and unlock your device or IP for secure access.
Summary
| Issue | Remove and re-add the email account |
| Incorrect email login credentials | Update your password in email settings |
| SMTP authentication not enabled | Enable authentication under SMTP settings |
| Wrong SMTP port or security settings | Use Port 465 (SSL) or 587 (TLS) |
| Outdated device software | Update iOS, iPadOS, or macOS |
| Corrupt email configuration | Remove and re-add email account |
Our Scope of Support
If you’re stuck and need any additional guidance or support, here’s an outline of what we can do and what is not within our Scope of Support.
We can assist with:
- Help interpreting settings
- Guiding through step-by-step fixes
- Checking DNS and server reachability
- Confirming whether the settings look valid
Advanced Support (Paid Services)
We may assist with some services that require advanced support.
- Deep server log analysis
- Third-party server troubleshooting
- Custom mail server configuration
We do not directly control, fix or assist with:
- Resetting local device credentials
- Managing ISP or corporate mail filters
- Fixing non-1-grid server issues
FAQs
Q. Why does this error happen after a password change?
Because devices still try to log in with old credentials.
Q. Do I need SMTP authentication on all accounts?
Yes, most mail servers require it to send mail securely.
Q. Can this error be on the server-side?
Yes, especially if your provider blocks untrusted clients or IPs.
Q. Will removing and re-adding the account delete emails?
No, as your email data stays on the server (for IMAP accounts) and will resync.
Additional Resources
Troubleshooting Email on Apple Devices
Understanding DNS Records
How to Fix “Cannot Verify Certificate” Errors
Need Additional Support?
We’re Here to Help:
Fixing an email address rejection error on the server doesn’t have to feel technical with this easy-to-reference guide. Stuck? Check out our Scope of Support, and then contact our Support Team for further clarity and guidance (https://1grid.co.za/contact-us/). We’re ready to see how we can help!