How to fix email problems: causes and solutions

Email is supposed to just work, so it is especially frustrating when a message does not arrive or ends up in spam. Fortunately, you can fix email problems yourself in most cases. This article walks you through the six most common situations: you cannot send, you receive nothing, your mail lands in the recipient's spam, your mailbox is full, your attachments get blocked, or one specific recipient never gets your message. For each problem you get the likely cause and a clear set of steps.

Fix email problems: start with these quick checks

Before you dive into the technical details, rule out the simple causes with a few checks. Often you find the problem right here.

• Log in to webmail at ljpc.email and send a test message to yourself. If that works, the problem is in your email program or device, not in the mailbox itself.
• Check your password. If you changed it recently, update it on all your devices: phone, laptop and tablet.
• Check your internet connection and, if possible, try a different network.
• Note the exact error message or, if a message was refused, the full bounce (the automatic return message). That text usually points straight to the cause.

You cannot send email

If you can receive but not send, the cause is almost always the outgoing server (SMTP) or the authentication. Check the outgoing settings in your email program:

• Outgoing server (SMTP): ljpc.email.
• Port: 465 with SSL/TLS, or 587 with STARTTLS.
• Authentication: on. The outgoing server asks for the same username (your full email address) and the same password as the incoming server.

The most common mistake is that authentication for outgoing mail is switched off. Without authentication the server refuses your message, because otherwise anyone could send through the server unasked.

Still no luck? Some networks and providers block port 25, and sometimes port 587, to curb spam. Port 25 is meant for traffic between mail servers, not for sending from your program. So use 465 or 587, or test through webmail to see whether your network is the culprit.

Unsure about a setting? Our guide on setting up email on your phone and computer lists all the server addresses and ports.

You receive no email

If nothing comes in, work through these three causes: the MX records, the mailbox itself and the spam filter.

Check the MX records

MX records tell the rest of the world which server receives the email for your domain. If they point to the wrong place, for example still to your previous provider or to an email service you no longer use, incoming mail does not reach LJPc. When your mail runs at LJPc, Plesk sets the correct MX records automatically. You can see the current value in Plesk under DNS Settings, or through a DNS lookup. For more background, read our explanation of the MX record.

Does the mailbox still exist?

Check that the email address is spelled correctly and that the mailbox still exists. A deleted or renamed mailbox rejects new messages. You manage your addresses in the customer portal or in Plesk. See also our guide on creating an email address in Plesk.

Is the message in the spam filter?

If you have a spam filter active, a message can land in quarantine instead of your inbox. Review the quarantine, release the sender and, if needed, add them to your allowlist (list of safe senders), so it comes through straight away next time. Also check the Junk or Spam folder in your email program.

Your email lands in the recipient's spam

If your outgoing mail ends up in the recipient's spam, the receiving server doubts whether your message is genuine. The three DNS records that decide this are SPF, DKIM and DMARC. If they are missing or set up incorrectly, filters judge more strictly.

• SPF: publish a TXT record that allows LJPc's mail servers. For LJPc mail that is v=spf1 include:_spf.ljpc.network -all. Read more in our explanation of the SPF record.
• DKIM: switch on DKIM in Plesk through the Mail tab and Mail Settings. Plesk then creates the key automatically and publishes the matching TXT record. Read more about DKIM.
• DMARC: add a TXT record at _dmarc and start with v=DMARC1; p=none; to monitor. Once everything works, tighten it step by step to quarantine or reject. See our explanation of DMARC.

If SPF, DKIM and DMARC are correct and your mail still lands in spam, check whether the sending IP address is on a blocklist (blacklist). With shared hosting you share the outgoing IP address with other customers, and LJPc manages that address. If you find a listing, contact support so we can arrange the removal. Keep your messages businesslike as well, and avoid typical spam signals such as lots of capital letters, a misleading subject or a single large image with no text.

Error message: mailbox full

The message mailbox full or quota exceeded means there is no room left to store messages. The key question is who exactly is full.

If you get this message when receiving, your storage is full. LJPc applies no hard limit per mailbox, but all your mailboxes, website files and databases share the storage of your hosting package (5, 20 or 50 GB) together. Once the package is full, no more mail fits.

Check your usage in Plesk. On the home page and under Statistics you can see how much disk space you use. Free up space by deleting large or old messages, empty the Trash and Spam folders, or choose a larger package if you consistently need more.

If you see mailbox full when sending instead, the recipient's mailbox is full. You cannot fix that yourself: wait a while and try again later, or let the recipient know through another channel that their mailbox is full.

Attachments get blocked or do not arrive

Attachments fail on two things: the size of the message and the type of file.

Message too large

Every mail server applies a maximum message size, attachments included. Both the sender's server and the recipient's server set a limit, and the lower of the two applies. In practice that limit sits around 20 to 25 MB per message at many services.

Note that an attachment is encoded before it is sent, which makes it around a third larger. A 20 MB file therefore weighs close to 27 MB in transit. So count on roughly three quarters of the limit in real file size. For larger files, use a download link or a cloud service and send only the link.

Blocked file type

Executable files and scripts, such as .exe, .bat, .cmd, .js and .vbs, are stopped for security reasons by the virus and spam filter, even when they sit inside a .zip. Renaming does not help and is not advisable. If you do need to share such a file, put it in a secure download location and send the link.

Email does not reach one specific recipient

If your mail arrives everywhere except with one person or one domain, the cause is usually on the receiving side. Work through these steps:

1. Read the bounce. If you get an automatic return message, it states a reason and often an error code. That text is your best clue.
2. Check the address for a typo.
3. Ask the recipient to add your address to their allowlist (safe senders). Sometimes their own spam filter is holding you back.
4. Send a test from webmail. If that arrives, the problem is in your email program.

If it keeps going wrong to that one address, gather the bounce, the time and the receiving domain and contact support. We can see in the mail logs what happens at delivery.

Quick overview

Cannot work it out? Feel free to contact support and we will help you further.