You send an email and it never gets a reply. You mention it later and the other person says they never got it — or they find it in their spam folder days later. Your emails are being treated as junk by other people’s email systems, even though they are completely ordinary messages.
What is probably happening
Email providers use automated systems to decide whether incoming messages are spam or genuine. These systems are not perfect, and legitimate emails get caught by them regularly. The reasons vary:
- Your email domain or address has a low trust score. If you have a personal website with its own email address ([email protected]), and that address is new or rarely used, spam filters may not trust it yet.
- Something in your message triggered a filter. Certain phrases, large numbers of links, or attachments can make an email look suspicious to automated systems.
- The recipient’s spam settings are very strict. Some organisations and individuals set their filters to catch anything even slightly unfamiliar.
- Your email went to the wrong folder. Some email apps sort messages into categories automatically — Gmail’s Promotions or Social tabs, for example — which people sometimes miss.
If you use a standard personal email (Gmail, Outlook, etc.)
If you send from a Gmail, Outlook, Hotmail, Yahoo, or similar large provider, your email being marked as spam is usually not a sending problem on your end — it is about how the recipient’s filters work.
The most effective thing you can do is ask the recipient to mark your email as Not Spam (or Not Junk) and add your address to their contacts. This teaches their email system that messages from you are legitimate and should reach the inbox in future.
Check whether it is landing in a tab rather than spam
Before concluding an email went to spam, ask the recipient to check their tabs. In Gmail, messages you might expect in the inbox often go to the Promotions or Social tab instead. These tabs appear at the top of the inbox. The recipient can drag the email from the tab to the Main inbox, which tells Gmail to send future messages from you there instead.
What to try on your end
Step 1. Check your email does not look like spam.
Review the message you sent. Does it have an unusual number of exclamation marks or capital letters? Does it contain links to websites? Does it have large images or attachments? Spam filters flag all of these. For important messages, plainer text with fewer links and no attachments (unless necessary) is more likely to arrive in the inbox.
Step 2. Check your subject line.
Subject lines with phrases like “urgent”, “free”, “winner”, “important notice”, “verify your account”, or anything that sounds like a marketing message are more likely to be flagged. Use a straightforward, specific subject line.
Step 3. Make sure your email signature does not have too many links.
A signature with five or six links to social media, websites, and phone numbers can trigger spam filters. Simplify your signature if you have one.
Step 4. Ask the recipient to whitelist your address.
In most email systems, adding an address to Contacts or to a Safe Senders list (in Outlook) ensures messages from that address always reach the inbox. Ask the person you are emailing regularly to add your address to their contacts.
If you have your own email address (e.g. [email protected])
Custom domain email addresses can have legitimate deliverability problems that are harder to fix without technical help. The main issues involve settings called SPF, DKIM, and DMARC — these are records your email provider or website host can set up to prove your emails are genuine. If you are not technical, contact your web host or email provider and ask them to check whether these records are set up correctly for your domain.
What NOT to do
- Do not add dozens of recipients at once to a message — sending to many people simultaneously is a spam pattern that filters flag.
- Do not resend the same message multiple times if it went to spam — this makes the problem worse.
- Do not use image-heavy emails as a workaround — some people’s email clients do not load images by default, and heavily image-based emails score poorly with spam filters.
When to stop and seek help
If emails from your custom domain consistently fail to reach inboxes even after technical settings are checked, the domain’s reputation may have been affected — possibly because someone else sent spam using the same domain previously. This is a situation for your email host’s support team.
If this did not work
For one-off important messages that keep going to spam, a practical workaround is to send from a well-established personal Gmail or Outlook account instead, or to call or text the person to tell them to check their spam folder. The recipient marking your email as Not Spam is still the most reliable long-term fix.
Frequently asked questions
Can I check whether my email went to spam before the recipient does?
Not directly. You will not see a delivery failure message if the email was accepted by the recipient’s server — spam filtering happens after delivery. You can send a test email to a second account you control to see how it is handled.
My reply to someone is going to their spam. Why?
Even replies can be caught by filters, particularly if the original conversation was months ago or if the recipient’s settings are strict. Ask them to add your address to their safe senders list or contacts.
Does this mean my email account is blacklisted?
For most personal users on major providers, no. Blacklisting is a problem that affects email servers sending bulk mail, not individual accounts. The more likely explanation is message content or unfamiliar sender.
Will it help to write “not spam” in the subject line?
No. This does not help and may make things worse.
Why did my email reach someone’s inbox last week but go to spam this week?
Spam filters update continuously. A message that passed one week may be caught by a newly updated rule the next week. Content changes, link changes, or changes to your email provider’s reputation can all affect this.