When business email stops working, it can disrupt communication with customers, suppliers and employees. You may find that messages remain in the Outbox, emails are rejected, customers cannot send messages to your company, or outgoing emails keep returning with delivery failure notifications.
If your business uses cPanel hosting, several tools are available to help identify and resolve common email problems. These include Email Accounts, Email Deliverability, Email Routing, Zone Editor and Track Delivery.
However, email problems are not always caused by the same issue. Incorrect passwords, full mailboxes, DNS configuration errors, authentication failures and server restrictions can all affect email communication.
This guide explains how to troubleshoot email that is not sending or receiving in cPanel, how to check the important settings and when to contact your hosting provider for assistance.
If you need reliable professional email for your organisation, you can also explore Tremhost Business Email Hosting.
1. Identify Whether the Problem Is Sending or Receiving
Before changing anything in cPanel, establish exactly what is happening.
There are two main types of email problems.
Outgoing email problems occur when you cannot send messages to other people. You may see an error in Outlook, receive a delivery failure notification or find that messages remain queued.
Incoming email problems occur when other people cannot send messages to your business address. Messages may bounce back to the sender, fail to arrive or be delivered to the wrong mailbox.
There may also be a situation where outgoing email works but incoming email does not, or vice versa.
To identify the problem, perform two simple tests. First, send a message from your business mailbox to an external address that you can access. Then send a message from that external address back to your business mailbox.
Record the results, including any error messages. This will help you determine which part of the email system needs investigation.
2. Check That Your Email Account Exists in cPanel
An email account cannot send or receive messages if it has not been created correctly or is no longer active.
Log in to your cPanel account and navigate to:
cPanel → Email → Email Accounts
Locate the email address experiencing the problem.
Check that the account exists and that you can access its management settings. If the account has been deleted, recreate it using the correct address.
If the mailbox exists but the user cannot log in, check whether the password is correct. You can reset the password through the account management interface if necessary.
Use a strong, unique password and update the saved credentials in Outlook, your mobile device or any other application connected to the mailbox.
Do not confuse a mailbox password problem with a DNS or server problem. If webmail works but Outlook does not, the issue may be with the email application’s configuration rather than the mailbox itself.
3. Check Your Email Storage and Mailbox Quota
A full mailbox can prevent users from receiving new messages.
In cPanel, open:
Email → Email Accounts
Find the affected mailbox and review its storage usage.
If the mailbox is approaching or has reached its storage limit, consider removing unnecessary messages, downloading important attachments or increasing the mailbox allocation if your hosting package allows it.
Before deleting messages, ensure that important business correspondence has been backed up or retained according to your organisation’s requirements.
Remember that deleting messages from one email application may synchronise the deletion across other devices when using IMAP.
Also check whether the overall hosting account has reached its disk quota. A mailbox may have an individual limit, but the hosting account itself can also have storage restrictions.
4. Check Your MX Records
MX records, or Mail Exchange records, tell other mail servers where to deliver incoming messages for your domain.
If your MX records point to the wrong mail server, incoming email may not reach your cPanel account.
To inspect the configuration, open:
cPanel → Domains → Zone Editor
Find your domain and select the option to manage its DNS records.
Locate the MX records and compare them with the exact values supplied by your email hosting provider.
Check that the destination hostname is correct and that the priority values match the provider’s instructions.
A lower numerical MX priority represents a higher preference when multiple mail exchangers are configured.
Do not copy MX values from another hosting account. The correct destination depends on your email service.
What if your website and email use different providers?
This is an important situation.
Your website may be hosted on one server while your email is hosted through Microsoft 365, Google Workspace or another email provider.
If this is the case, your MX records must point to the external email service, not automatically to the web hosting server.
Changing the MX records to the wrong destination can interrupt incoming business email.
Before changing them, confirm which provider is responsible for receiving messages for your domain.
5. Check Email Routing in cPanel
Even when MX records appear correct, cPanel may be configured to route incoming messages incorrectly.
Open:
cPanel → Email → Email Routing
Select the affected domain.
You may see the following options:
Automatically Detect Configuration: Allows cPanel to determine the appropriate routing configuration from the domain’s local MX records. This is generally the recommended starting point.
Local Mail Exchanger: Use this when the domain’s email is handled by the local cPanel server.
Remote Mail Exchanger: Use this when another server or external provider handles the domain’s email.
Backup Mail Exchanger: Use this when the cPanel server is intended to act as a backup mail exchanger.
The correct setting depends on where your mailboxes actually reside.
For example, if your domain’s email is hosted on the cPanel server, it will generally need local routing. If your business uses an external email service, it will generally need remote routing.
Do not change this setting simply to experiment. An incorrect routing configuration can prevent your domain from receiving email.
If you are unsure which option applies, contact your hosting provider before making changes.
6. Use Email Deliverability to Check SPF and DKIM
Incorrect email authentication is another common cause of sending and deliverability problems.
cPanel includes a tool called Email Deliverability that checks mail-related DNS records and provides recommended configurations.
Navigate to:
cPanel → Email → Email Deliverability
Select the affected domain.
The interface displays the status of supported authentication records, including SPF and DKIM.
If cPanel identifies a problem, review the suggested configuration.
Where the domain’s DNS is managed by the same hosting provider, the system may offer a repair option.
If the DNS is managed externally, copy the exact recommended records and publish them in the authoritative DNS zone.
For example, your domain may use Cloudflare for DNS while its mailboxes are hosted on a cPanel server. In this situation, cPanel may generate the correct SPF and DKIM values, but you must publish them in Cloudflare.
Do not create additional SPF records simply because the existing one appears incorrect. Update the existing policy appropriately and ensure that all legitimate sending services are included.
What about DMARC?
DMARC is another important email authentication standard.
It allows domain owners to publish a policy for handling messages that fail relevant authentication and alignment checks. It also supports reporting that can help administrators understand how their domain is being used.
DMARC is normally configured as a TXT record under:
_dmarc.yourdomain.comThe exact policy should be chosen after checking all legitimate email-sending services.
For a deeper explanation, read How to Set Up SPF, DKIM and DMARC for Your Business Domain.
7. Check the SMTP Settings in Outlook and Other Email Applications
Sometimes the mailbox works perfectly in webmail, but users cannot send messages through Outlook or their mobile devices.
This often points to an incorrect email application configuration.
For outgoing messages, the application must connect to the correct SMTP server using the settings supplied by the hosting provider.
Typical secure SMTP configurations may use:
| Setting | Common configuration |
|---|---|
| SMTP server | Provider-supplied mail hostname |
| SMTP port | 465 or 587 |
| Authentication | Required |
| Username | Full email address |
| Password | Mailbox password |
| Encryption | SSL/TLS or STARTTLS, according to the port |
These are common configurations, not universal settings. Always use the exact server hostname and connection details supplied for your hosting account.
Also confirm that SMTP authentication is enabled. An email application may be able to connect to the server but fail to send if it does not authenticate correctly.
If incoming email also fails, check the IMAP settings separately.
8. Use Track Delivery to Find Out What Happened to an Email
One of the most useful troubleshooting tools in cPanel is Track Delivery.
It helps administrators investigate the delivery status of messages sent from or received by a cPanel account.
Navigate to:
cPanel → Email → Track Delivery
If the feature is available, enter the recipient’s email address and click Run Report.
Review the delivery results and look for the relevant message.
Depending on the server configuration, you may see statuses such as:
Success: The server reports that the message was delivered to the next destination or the relevant local mailbox.
Deferred: The server has temporarily delayed delivery and may attempt it again.
Error: The message encountered a delivery problem.
Rejected: The message was refused during the SMTP delivery process.
Filtered: The receiving system accepted the message but filtering may have prevented it from reaching the intended inbox.
Open the information details for the message and examine the result.
For example, a deferred message may indicate that the receiving server is temporarily unavailable. A rejected message may contain information about authentication, policy restrictions or server reputation.
A successful result does not always mean the message reached the recipient’s primary inbox. The receiving provider may still place it in spam or another folder.
If Track Delivery is not available in your cPanel account, ask your hosting provider whether the feature is enabled.
9. Check Whether Your Domain Is Being Used to Send Spam
If your business suddenly experiences hundreds of failed delivery notifications, unusual outgoing traffic or reports of spam being sent from your domain, investigate the possibility of a compromised mailbox.
A compromised email account can be used to send large volumes of unwanted messages.
This can result in:
- Unusual outgoing email activity.
- Mailbox or account restrictions.
- Failed delivery notifications.
- Spam complaints.
- Reputation problems for the sending infrastructure.
- Temporary restrictions imposed by the hosting provider.
Open Email Accounts and review the affected mailboxes. If suspicious activity is suspected, change the password from a trusted device and review account access.
Enable two-factor authentication where supported.
Also ask your hosting provider to inspect server logs and investigate whether the account has been restricted because of suspicious sending activity.
Do not simply increase the sending limit to solve the problem. If the account is compromised, allowing it to continue sending messages could make the situation worse.
10. Check for DNS Problems Outside cPanel
One of the most common mistakes when troubleshooting email is updating DNS records in the wrong location.
For example, a business may register a domain through one company, host its website through another and manage DNS through Cloudflare.
If Cloudflare is authoritative for the domain, adding an SPF record only in the cPanel Zone Editor may not update the records that receiving mail servers actually see.
You must publish the required records in the authoritative DNS zone.
To identify your domain’s nameservers, you can use a DNS lookup tool or run:
dig NS yourdomain.comYou can also check the MX records using:
dig MX yourdomain.comTo inspect an SPF record:
dig TXT yourdomain.comAnd to check a DMARC record:
dig TXT _dmarc.yourdomain.comThese commands are examples for administrators using a terminal with DNS lookup utilities installed.
If the records returned by DNS do not match the configuration supplied by your provider, investigate the authoritative DNS zone and correct the discrepancy.
Do not change nameservers just to repair an email record. Changing nameservers can affect your website and every other DNS-dependent service.
11. Understand Common cPanel Email Errors
When an email fails, the server may return a diagnostic message. The exact meaning depends on the receiving mail server, but the following examples can help identify the problem.
| Error or message | Possible explanation |
|---|---|
| 550 5.1.1 | Recipient address may not exist |
| 552 5.2.2 | Recipient mailbox may be full |
| 421 or 451 | Temporary server or connection issue |
| 550 5.7.1 | Message rejected because of a security or policy restriction |
| Authentication failed | Incorrect credentials or SMTP authentication problem |
| SPF fail | Sending server did not pass the domain’s SPF check |
| DKIM fail | Message signature could not be verified |
| Connection timed out | Server, network or firewall connection issue |
These are general examples. Always examine the complete error message rather than relying on the numerical code alone.
For instance, a 550 5.7.1 response can have different causes depending on the server’s rejection policy.
If you are unsure how to interpret a delivery failure, preserve the full bounce message and provide it to your hosting provider.
12. Test Email After Making Changes
After correcting the configuration, perform a fresh test.
Send a message from the affected mailbox to an external address you control.
Check that the recipient receives it, then reply to the original message.
If possible, test with more than one receiving provider, such as Gmail and Outlook.
If you changed authentication records, inspect the message headers or use the recipient’s message details to check SPF, DKIM and DMARC results.
Ideally, the authentication checks should pass and the messages should be accepted by the receiving providers.
Also test webmail and any desktop or mobile applications used by employees.
Do not assume that correcting one mailbox automatically fixes every email account on the domain.
When Should You Contact Your Hosting Provider?
Some email problems can be resolved through cPanel, but others require access to server-level settings that ordinary hosting customers cannot change.
Contact your hosting provider if:
- Track Delivery shows repeated server-level errors.
- Your outgoing mail has been restricted.
- Your server appears to be blocked by a receiving provider.
- Multiple mailboxes suddenly stop working.
- You cannot determine the correct MX, SPF or DKIM values.
- Email Routing settings are unclear.
- Messages are being rejected despite correct account credentials and DNS.
- You suspect a compromised mailbox or wider server security issue.
When contacting support, provide the affected email address, approximate time of the failed message, recipient address, full error message and any relevant Track Delivery information.
Never send your mailbox password in a support ticket.
Providing detailed diagnostic information makes it easier for the technical team to investigate the issue.
Frequently Asked Questions About cPanel Email Problems
Why can I receive emails but not send them?
This may be caused by incorrect SMTP settings, an authentication problem, a sending restriction or a server-side issue. Check your email application’s outgoing server details and inspect Track Delivery for failed messages.
Why can I send emails but not receive them?
Check your MX records, mailbox quota and Email Routing configuration. If your MX records point to the wrong server, incoming messages may not reach the correct mailboxes.
Why does Outlook say it cannot connect to the outgoing mail server?
Check the SMTP hostname, port, encryption method, username and password. Confirm that SMTP authentication is enabled and that you are using the settings supplied by your hosting provider.
What is Email Deliverability in cPanel?
Email Deliverability is a cPanel tool that checks mail-related DNS records and provides suggested configurations for supported authentication records such as SPF and DKIM.
What is Track Delivery in cPanel?
Track Delivery provides a report of email messages sent from and received by a cPanel account. It can help identify successful, deferred, rejected and failed deliveries when the hosting provider has enabled the feature.
Can incorrect MX records stop email from working?
Yes. MX records direct incoming messages to the appropriate mail servers. If they point to the wrong destination, email may fail to reach your mailbox.
Should I select Local Mail Exchanger or Remote Mail Exchanger?
Select the option that reflects where your email is actually hosted. Local Mail Exchanger is generally appropriate when cPanel handles your mailboxes, while Remote Mail Exchanger is used when an external provider handles incoming email. If unsure, contact your hosting provider.
Does changing DNS affect my website?
Changing email-specific records such as MX and certain TXT records normally does not require changing your website’s A records. However, changing nameservers or modifying unrelated DNS records can affect your website. Always check the intended changes before saving.
Can spam activity cause my cPanel email to stop working?
Yes. A compromised mailbox or unusual sending activity can lead to restrictions or reputation problems. Investigate the cause, secure the affected accounts and contact your hosting provider.
Final Thoughts: Keep Your Business Email Working Reliably
When business email stops working, the cause may be a simple password problem or a more complicated issue involving DNS, mail routing, authentication or server restrictions.
The best approach is to troubleshoot systematically.
Start by identifying whether the problem affects sending or receiving. Check the mailbox, storage quota, MX records and Email Routing settings. Use Email Deliverability to inspect SPF and DKIM, and use Track Delivery to investigate failed messages.
Most importantly, avoid making random DNS changes. Incorrect MX, SPF and DKIM records can create additional problems, particularly when your website and email are managed by different providers.
If your organisation needs professional email hosting with domain authentication, spam filtering and technical support, explore Tremhost Business Email Hosting.
A properly configured email environment helps your team communicate with customers, suppliers and business partners more reliably.
