Why Are My Emails Not Coming Through?

Someone says they sent you an email, and nothing has arrived. Or a customer says your quote never reached them. Either way, the email went one of three places: it arrived somewhere you are not looking, it was rejected and bounced, or it never left the sender’s outbox. Finding which one it was usually takes a few minutes. Guessing usually takes a day.

This is the order we check things in when an Australian business tells us their emails are not coming through. Start at the top. Most problems are solved before the DNS section.

Three questions to answer first

1. Is it one sender, or everyone? If mail from one person is missing, the problem is usually a filter, a block or their own server. If nothing at all has arrived since yesterday, look at the mailbox, the domain or the MX records.
2. Did the sender get a bounce message? A bounce means your mail server rejected the message, and the bounce says why. No bounce usually means the email was delivered, just not where you expected.
3. Is it missing from webmail too, or only your phone? If webmail has the message, the mailbox is fine. The problem is the app on the phone or computer.

Ask the sender to send a short test with a plain subject line, no attachment and no links. Note the time they sent it. That one test message makes every step below easier to check.

Check junk, filters and other folders

The most common answer is that the email arrived, but not in the inbox. Search the whole mailbox for the sender’s address, not just the inbox view.

• Gmail: check Spam, the Promotions and Updates tabs, and All Mail. Under Settings, check Filters and Blocked Addresses, and whether forwarding sends a copy elsewhere and archives the original.
• Outlook: check the Junk Email folder and the Other tab if Focused Inbox is on. Open Rules and look for anything that moves or deletes mail. Check the Blocked Senders list under Junk Email options.
• Microsoft 365: messages flagged as spam, phishing or malware can be held in quarantine instead of Junk. Your administrator can release them from the quarantine page in the Microsoft Defender portal.
• cPanel mailboxes: check the spam folder in webmail, then Email Filters and Global Email Filters in cPanel. A filter set up years ago to stop one newsletter can catch far more than intended.

If you find the message in junk, mark it as not spam and add the sender to your contacts. That teaches the filter for next time.

Check webmail before you blame the phone

Log in to webmail in a browser. If the message is there, the mailbox received it and the phone or desktop app is the problem. Common causes are:

• an old password saved in the app after the mailbox password was changed;
• the account added as POP instead of IMAP, so another device downloaded and removed the message first;
• on iPhone, Fetch New Data set to manual, or Low Power Mode pausing background mail; and
• Outlook on a computer left in Work Offline mode.

Removing the account from the phone and adding it again with the server names from your mail provider fixes most of these. For a cPanel mailbox, the correct settings are listed next to the mailbox in cPanel. Our guide to setting up a business email address covers adding it to a phone.

Is the mailbox full?

When a mailbox reaches its storage limit, new mail is rejected. The sender gets a bounce saying the mailbox is full or over quota. You usually get no warning at all, apart from the silence.

In cPanel, Email Disk Usage shows which folders are taking the space. Sent items and old attachments are usually the biggest. Empty the trash after deleting, because deleted mail still counts until it is purged.

On shared cPanel hosting, your mailboxes share the plan’s SSD storage with the website: 10GB on Basic, 25GB on Standard and 50GB on Advanced. If mail keeps filling the account, moving up a plan gives it more room. If one mailbox needs to keep years of history, a larger Microsoft 365 mailbox may be the better home for it.

Check the domain has not expired

If nothing is arriving from anyone, and the website is down too, check the domain. An expired domain stops receiving mail the moment it lapses. Renewal reminders often go to an old address, or to the developer who registered it.

Use a WHOIS lookup to see the expiry date and who the registrar is. Renew it straight away. Mail will start flowing again once DNS updates, but messages sent while the domain was expired are usually lost.

Check where your MX records point

MX records tell the rest of the internet which server receives mail for your domain. If they point to the wrong place, mail is delivered to a mailbox you no longer use, or it bounces.

This is the most common cause after a change. Typical examples are moving the website to a new host, moving email to Microsoft 365, or changing nameservers during a domain transfer. The website moves and works, but the MX records still point at the old mail server, or the new nameservers have no MX records at all.

• Look up your domain’s MX records with a free tool such as Google Admin Toolbox Dig or the MXToolbox MX lookup.
• Compare them with what your mail provider says they should be. For cPanel mail, that is your hosting server. For Microsoft 365, it ends in mail.protection.outlook.com.
• Remove any old MX records left behind. Two sets of MX records pointing at different providers split your mail, so some messages land in each.

Change MX records in the DNS zone your nameservers use. Editing DNS at the registrar has no effect if the nameservers point at your host, and the other way around. DNS changes can take a few hours to reach everyone, so allow time before testing again.

Read the bounce message

If the sender got a bounce, ask them to forward the whole thing. It looks technical, but there is usually one line that explains the problem. Common ones are:

• 550 5.1.1 user unknown: the address does not exist. Check the spelling, and that the mailbox was not deleted or renamed.
• 552 mailbox full or over quota: the mailbox is out of space. See the mailbox section above.
• 554 or 550 5.7.1 rejected: the receiving server refused the message as spam or because of a policy. The rest of the line usually names the reason or a blocklist.
• 550 5.7.26 or “unauthenticated”: the message failed SPF, DKIM or DMARC checks. The sending domain’s DNS needs fixing, which is covered below.

When your emails are not reaching other people

Sometimes the problem is the other way around: you send, and your customers never see it. Gmail, Outlook.com and most business mail systems now check whether a message really came from the domain it claims to be from. Mail that fails those checks goes to junk or is rejected outright.

Three DNS records do that job:

• SPF lists the servers allowed to send mail for your domain. A domain must have only one SPF record. Two records starting with v=spf1 break SPF entirely, which often happens when someone adds Microsoft 365 or a newsletter tool and creates a second record instead of editing the first.
• DKIM adds a digital signature to each message, so the receiving server can confirm it was not changed or forged. cPanel and Microsoft 365 can each generate the record for you.
• DMARC tells receiving servers what to do with mail that fails SPF and DKIM, and where to send reports. Start with a policy of p=none so you can see what is happening before you tell servers to reject anything.

On cPanel hosting, the Email Deliverability tool shows whether SPF and DKIM are valid for each domain and offers to fix them. On Microsoft 365, the Microsoft 365 admin centre shows the records the domain needs under Settings, then Domains. To check any domain from outside, use the MXToolbox SPF lookup and DMARC lookup. Check every service that sends as your domain, including your website, booking system, invoicing software and newsletter tool.

If your server’s IP address is on a blocklist, many receivers will refuse your mail until it is removed. The MXToolbox blacklist check tests your server’s IP or domain against the major blocklists. On shared hosting, contact us and we will look into it. On a VPS, the IP is yours to manage, and a missing reverse DNS record is a common reason mail is refused.

Emails stuck in the outbox

If messages sit in the outbox and never send, the email app cannot log in to the outgoing mail server. Check the outgoing server name, port and password in the account settings. The outgoing server usually needs the same full email address and password as the incoming one.

A large attachment can also block the outbox. Most mail servers limit the size of a single message, and one stuck email can hold up everything behind it. Delete it from the outbox, then send the file as a link from OneDrive, Google Drive or Dropbox instead.

Website forms that stop sending

Contact form and WooCommerce order emails often go missing because the website sends them without logging in to a real mailbox. To Gmail or Outlook, that looks like forged mail from your domain. Install an SMTP plugin in WordPress and connect it to a real mailbox on your domain, so the website sends mail the same way your email app does. Then send a test form and check it arrives.

Business email with your hosting

If your current provider leaves you guessing every time mail goes missing, it may be time to move. Every HSJ Host shared cPanel hosting plan includes business email on your own domain, hosted on our Sydney servers alongside your website.

• 10 email accounts on Basic, 25 on Standard and unlimited on Advanced;
• spam protection, virus filtering, webmail and email forwarding on every plan;
• cPanel tools such as Email Deliverability and Track Delivery, so you can check SPF and DKIM and trace a message yourself; and
• 24/7 Australian support when you would rather we traced it for you.

Plans start from $8.79 a month, GST inclusive, with no setup fee. Our guide to setting up a business email address walks through creating the first mailbox. If your website is hosted somewhere else and you only want to move the mail, business email hosting starts at $4.35 a month, GST inclusive, and moving mailboxes from another cPanel email host is free.

What to send support

If you have worked through the list and mail is still missing, a few details make the problem much faster to find:

• the sender’s address and your address;
• the date and time the test message was sent;
• the full bounce message, if there was one; and
• whether it is one sender or everyone, and whether webmail shows the same problem.

With those, we can trace the message in the server’s mail logs and tell you whether it arrived, was rejected or was never sent. cPanel users can also run Track Delivery themselves to see the same record.

Next step

If your mail is on HSJ Host, open a support ticket with the details above and we will trace it. If you want your website and business email in one place with Australian support, compare the plans on shared cPanel hosting, or business email hosting if the website stays where it is. If your team runs on Microsoft 365 and mailbox, sign-in or delivery problems keep coming back, Microsoft 365 support covers that day-to-day administration. Moving mail from another provider? Plan the MX change with Microsoft 365 migration so nothing goes missing during the switch.