“It was not sent” and “the recipient did not receive it” are different problems. The first often concerns the connection or authentication between the client and SMTP server; the second points to later delivery stages.
Use the error message, timestamp and recipient domain to check the connection, authentication, sender domain and bounce reason, without sharing passwords or confidential email content.
1. First identify where the email stopped
| Status | First check |
|---|---|
| The message remains in Outbox | A kliens kapcsolata az SMTP-szerverrel |
| Immediate sending error | SMTP address, port, encryption and authentication |
| Sent, then bounced | The complete error code and text from the bounce message |
| Sent without errors, but not visible | Recipient-side spam filtering, rules and server logs |
2. If the client cannot send the message
- Check that the correct SMTP server is assigned to the account.
- Check the server name, port, encryption and authentication method against the provider's details.
- Check the required username format; some services expect the full email address.
- Try sending a small test email without attachments to your own external account.
3. If you received a bounce message
| Hibacsoport | Mit jelenthet? |
|---|---|
| 4xx | Temporary error or rejection; the exact message matters |
| 5xx | May indicate permanent rejection, such as an invalid address, policy or authentication issue |
| Quota / mailbox full | The recipient's mailbox or service is full |
| Policy / authentication | Investigate sender identity, SPF/DKIM/DMARC or recipient policies |
4. Request targeted help
- Provide the sending date, time and time zone.
- Provide the sender and recipient domains, plus the exact error text or code.
- State whether sending started from webmail, Thunderbird or an application.
- Do not send passwords, access tokens or confidential email content.
