To stop important emails going to spam, mark them as "Not spam," add the sender to your contacts or safe senders list, and create a filter that never sends their mail to spam. Doing this consistently also trains your spam filter, so it learns which senders you trust and makes fewer mistakes over time.
Spam filters catch billions of unwanted messages, but they're not perfect. A client's invoice, a job offer or a password-reset email can end up in the wrong folder, and you may not notice until it's too late.
Check your spam folder regularly, at least once a week.
Mark legitimate mail as "Not spam" instead of just dragging it to your inbox.
Add trusted senders to your contacts or safe senders list.
Create a filter for senders you can't afford to miss.
Don't whitelist whole public domains like gmail.com; that lets in spammers too.
If it keeps happening, the sender may have a setup problem, and you can tell them how to fix it.
Why do important emails go to spam?
Spam filters score every incoming message on dozens of signals and move it to spam if the score crosses a threshold. A legitimate email can trip that threshold for reasons that have nothing to do with you.
Reason | What it looks like |
|---|---|
The sender is new to you | A first email from a new client, supplier or recruiter |
The sender's domain isn't authenticated | Missing or broken SPF, DKIM or DMARC records |
The sender's reputation is poor | Their domain or server was used for spam, or shares an IP with spammers |
The content looks risky | Invoices, payment requests, many links, large attachments or shortened URLs |
You (or others) reported similar mail | Filters learn from users marking messages as spam |
It looks like a forwarded or bulk message | Newsletters, automated notifications or mail sent via forwarding services |
As a recipient, you control the "new sender" and "what you report" signals. The authentication and reputation problems sit on the sender's side, which we cover below.
Be aware that invoices and payment emails are flagged often because scammers imitate them so heavily. If you send them yourself, our guide to payment reminder emails covers how to keep them out of spam.
How to whitelist a sender, app by app
"Whitelisting" (also called allowlisting or adding to safe senders) tells your email app to trust a specific address or domain. Here's how in the most common apps. Menu names change between versions, so look for similar wording if yours differs.
Gmail
Open the Spam folder, select the email and click Report not spam.
Add the sender to Google Contacts.
For senders you can't miss, create a filter: search for
from:name@company.com, click the filter icon in the search bar, choose Create filter, tick Never send it to Spam, then Create filter.
Outlook (Outlook.com and new Outlook)
In the Junk Email folder, select the message and choose Not junk.
Go to Settings → Mail → Junk email.
Under Safe senders and domains, click Add, enter the address or domain, and save.
In the classic Outlook desktop app, use Home → Junk → Junk E-mail Options → Safe Senders.
Apple Mail
In the Junk folder, select the email and click Not Junk (or move it to your inbox).
Add the sender to Contacts.
On a Mac, go to Mail → Settings → Junk Mail and make sure senders in your Contacts are exempt from junk filtering.
Yahoo Mail
In the Spam folder, select the email and click Not spam.
Add the sender to your Yahoo contacts.
For extra certainty, create a filter in Settings → More settings → Filters that moves their mail to your inbox.
How to train your spam filter
Modern spam filters learn from what you do. Every click on "Spam" or "Not spam" is feedback. A few habits make that feedback count.
Use the buttons, don't just drag. Moving an email out of spam by dragging may not teach the filter anything. "Not spam" and "Report spam" send a clear signal.
Be consistent. If you mark a sender as spam one week and rescue them the next, the filter can't learn a pattern.
Reply to trusted senders. Many filters treat people you've written to as trusted.
Unsubscribe instead of reporting newsletters you signed up for but no longer want. Reporting legitimate mail you opted into confuses the filter and hurts honest senders.
Report real spam and phishing. Teaching the filter what's bad helps it separate the good.
Check spam weekly. Most providers empty the spam folder automatically after a set period, so a missed email can disappear for good.
Whitelist safely
Whitelisting tells your filter to look the other way, so use it carefully:
Whitelist specific addresses or company domains, not public ones like gmail.com or outlook.com. Anyone can create an address there.
Be wary of urgent "whitelist us" requests. A message asking you to add a sender to your safe list so you don't "miss important updates" can be a phishing tactic. Our guide to phishing protection and TLS encryption explains the warning signs.
Stay alert even with trusted senders. If a known contact's account is hacked, whitelisting means their phishing emails skip the filter. Check unexpected payment changes by phone.
Review your safe senders list once or twice a year and remove anyone you no longer deal with.
For admins: whitelisting across your organisation
If a key partner's mail keeps going to spam for everyone in your company, fixing it one inbox at a time won't scale. Most business email platforms let admins add an organisation-wide allowlist for specific domains or addresses. Use it sparingly:
Allow specific partner domains, never public email domains.
Prefer allowing mail that passes authentication (SPF, DKIM or DMARC) over allowing a domain outright, so spoofed mail from that domain is still caught.
Document every entry and review the list regularly.
Don't let users auto-forward spam-folder mail elsewhere to "rescue" it; our post on auto-forwarding work email explains the risks.
When the problem is the sender, not you
If the same sender lands in spam for you and your colleagues, the cause is probably on their side. A short, friendly note can help them fix it:
"Your recent emails have been landing in our spam folder. It may be worth checking your domain's SPF, DKIM and DMARC setup."
If that sender is you, these guides walk through the fixes:
And if your messages are being rejected outright rather than filtered, our guide to email bounce codes explains what the error means.
FAQ
How do I stop emails from a specific sender going to spam?
Mark one of their emails as "Not spam," add them to your contacts, and create a filter or safe-sender entry for their address.
How do I whitelist an email address in Gmail?
Search for from: followed by their address, click the filter icon, choose Create filter, tick "Never send it to Spam," and save. Adding them to your contacts helps too.
Why do my important emails keep going to junk?
Usually because the sender is new to you, their domain isn't properly authenticated, or the content looks like common scams. Marking the emails as not spam and whitelisting the sender usually fixes it for you.
Does marking an email as "Not spam" really help?
Yes. It's direct feedback to your filter and, at many providers, a signal about that sender's reputation.
Is it safe to whitelist a sender?
For specific, trusted addresses or company domains, yes. Don't whitelist public domains like gmail.com, and stay alert for unusual requests even from whitelisted senders.
What's the difference between a whitelist and a safe senders list?
Nothing meaningful. Whitelist, allowlist and safe senders list all mean a list of senders your filter should trust.
How often should I check my spam folder?
At least once a week. Many providers delete spam automatically after a period, so missed emails can disappear for good.
Business email that gets delivered, both ways
Whitelisting fixes what you receive. Your own email setup decides whether what you send reaches other people's inboxes. NevTan Mail is business email hosting on your own domain, with guided SPF, DKIM and DMARC setup so your messages are authenticated from day one, a dedicated Spam folder and search filters to find anything that slipped through, and secure business email features like TLS encryption and two-factor authentication.
Check business email pricing, start with free business email, or see how NevTan compares as a Gmail alternative for business or a Microsoft 365 alternative.
