Guide
How to fix email not sending or receiving
Email problems split into two groups: mail not arriving, usually caused by MX records, a full mailbox or filtering, and mail not sending, usually caused by wrong server settings, passwords, ports or authentication. Read any bounce message first, because it gives the exact reason. Then check DNS records, mailbox space and your email app settings in that order.
The journey
How an email travels
- You sendYour app connects to the outgoing server
- DNS lookupThe sender looks up the recipient MX record
- Recipient serverAccepts or rejects the message
- MailboxMessage is stored if there is room
- Reader appIMAP or webmail shows it
A fault at any step looks like missing email. Finding the step is the whole job.
Start here
Work out which problem you have
Before changing anything, be precise. Is it that you cannot receive, cannot send, or both? Does it affect one mailbox or all of them? One person or everybody? Does it happen with every sender or only a few? Does webmail work when your phone app does not? Each answer removes a branch of possible causes.
If webmail works but a phone or desktop app does not, the mailbox and server are fine and the fault is in the app settings or password. If mail fails everywhere, including webmail, look at DNS records, mailbox space and the server side. If only some senders cannot reach you, look at filtering, blocklists and authentication.
Always read the bounce message if you get one. It is an automatic reply that begins with something like Undelivered Mail Returned to Sender and contains a code and a reason in plain words. Most mysteries are solved by that single line.
Bounce codes
Reading common bounce messages
| Code or wording | Meaning | What to check |
|---|---|---|
| 550 User unknown | The address does not exist | Spelling, and that the mailbox is created |
| 552 Mailbox full | No space in the recipient mailbox | Delete or archive mail, or enlarge the quota |
| 550 Rejected, SPF failed | Sending server not allowed by the domain | SPF record. See the SPF, DKIM and DMARC guide |
| 554 Blocked or listed | Sender address is on a blocklist | Scan for compromise, request delisting |
| 421 Try again later | Temporary problem or rate limit | Wait and retry, check volume |
| Domain not found | Recipient domain has no valid DNS | Check the spelling of the domain |
| Authentication failed | Wrong username or password | Use the full address and the current password |
Unlimited email accounts on every plan
Create mailboxes on your own domain with spam protection included.
Not receiving
Fixing email that does not arrive
Test with webmail
Log in to webmail with the mailbox. If new mail is visible there, the mailbox receives fine and your app is the problem.
Check mailbox space
A full mailbox rejects new mail. Delete large messages, empty trash and junk, or archive old mail locally.
Check the spam folder and filters
Look in junk, and check for forwarding rules or filters that move or delete messages.
Check the MX records
The MX records for your domain must point at the mail server. If you recently changed nameservers or hosting, MX records may be missing or stale.
Confirm the domain is set to receive locally
If your mail is hosted elsewhere, such as another provider, the domain must be set to remote mail exchange, not local.
Ask the sender for the bounce
Their error message names the cause. Send it to us if it is unclear.
DNS
MX records, the most common cause of missing mail
MX records tell the world which server accepts mail for your domain. If they point at the wrong place, mail goes there instead of to you, or goes nowhere. This often happens after moving a website, changing nameservers, or adding a service that rewrites DNS. The website works and everyone forgets that email lived in the same DNS zone.
Look up your MX records with an online lookup tool and compare them with the details shown in your hosting control panel. Only one provider should receive your mail. Having MX records for two providers at the same priority splits mail between them, which looks like random messages vanishing.
DNS changes take time to spread, so after fixing records, allow a while. See our guide on fixing a site after a DNS change for how caching works, and setting up email on your domain for the correct records.
Not sending
Fixing email that will not send
Check the outgoing server settings
Use the outgoing server name shown in your hosting settings, with authentication on, and your full email address as the username.
Check the port and encryption
Use the secure ports shown in your settings, commonly 465 with SSL or 587 with STARTTLS. Port 25 is often blocked by home internet providers.
Re-enter the password
Passwords that changed, or were saved with a typing error, are a frequent cause. Type it fresh and test in webmail with the same password.
Check message size
Large attachments can exceed limits on either side. Try a short message with no attachment.
Check SPF and DKIM
Messages from your domain should be authorised. Without it, receivers may reject or junk them.
Test a different network
Some office and public networks block mail ports. Try mobile data.
Where to look
App problem or server problem
Likely the email app or device
- Webmail works normally
- Only one device has the problem
- Password prompts keep returning
- Started after a phone or app update
- Another network works
Likely DNS or the server
- Webmail also fails or shows nothing new
- Several people are affected
- Bounce messages mention domain or SPF
- Began after a hosting or DNS change
- Senders report delivery failures
Authentication
Why authentication decides whether mail is accepted
Receiving servers do not trust mail just because it claims to come from your domain. They check SPF, which lists the servers allowed to send for you, DKIM, which adds a signature, and DMARC, which says what to do if checks fail. Large providers increasingly reject or junk mail that fails these checks.
If your messages are reaching recipients as spam, or being rejected with an authentication error, this is the area to fix. Our guides on SPF, DKIM and DMARC and on stopping email going to spam explain the records and how to test them.
Our hosting includes spam protection and an external mail relay, which help keep outgoing mail from being limited by the problems that sometimes affect shared addresses. Even so, a correct SPF record and a clean sending history are still your part of the job.
Checklist
Email troubleshooting checklist
- Read the full bounce message
- Test the mailbox in webmail
- Check the quota and free some space
- Check spam, filters and forwarding rules
- Check MX records point to the right server
- Check SPF and DKIM records exist
- Use the full address as username
- Use secure ports shown in your settings
Prevention
Keeping email reliable
Watch mailbox size
Archive or delete old mail before the quota fills.
Protect your DNS
Keep a copy of your DNS records, especially MX, before changing providers.
Use strong passwords
A stolen password turns your address into a spam source and gets you blocklisted.
Set up authentication
SPF, DKIM and DMARC build trust with receiving servers.
Test after changes
Send yourself a test after any hosting or DNS change.
Ask us
Live chat can check the mailbox, logs and records quickly.
Getting help
What to send us when you need help
The faster we can see the problem, the faster it is solved. Tell us the email addresses involved, the time of a failed test, the exact wording of any bounce, whether webmail works and what you last changed. A screenshot of your app account settings, with the password hidden, is also useful.
If you suspect your mailbox has been compromised, change its password at once and tell us. Unexpected sent items, messages you did not write, or sudden bounce floods are all signs. Prompt action protects your domain reputation, which affects whether your mail reaches inboxes in the future.
FAQ
Common questions
Why can I send but not receive?
Usually the MX records, a full mailbox, or a filter. Check webmail, space and DNS in that order.
Why can I receive but not send?
Often wrong outgoing server settings, a blocked port, a bad password or an authentication problem.
Do I need SPF and DKIM?
Strongly recommended. Without them, many receivers junk or reject your mail.
Which ports should I use?
Use the secure ports shown in your hosting settings, commonly 465 with SSL or 587 with STARTTLS for sending.
How many mailboxes can I have?
Unlimited email accounts are included on every plan.
Keep reading
Related pages
Email that is set up properly from day one
Unlimited mailboxes, spam protection and live chat open 24/7.