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Gmail Blocking Your Emails or Sending Them to Spam? Causes and Fixes

Published 2026-11-03 ／ Updated 2026-11-03 ／ By Yuki Nakazawa

If Gmail is blocking your emails or your emails are going to spam, the cause is almost always one of three things: your domain isn't authenticated the way Gmail expects (SPF, DKIM, DMARC), your sending server's setup or reputation has a problem, or recipients are marking your mail as spam. The bounce message you get back usually tells you which one.

If instead you're the one not receiving mail in your own Gmail inbox, the fix is usually on your side: the Spam folder, an inbox tab, a filter, a forwarding or POP setting, or full storage. Both cases are covered below, so jump to the part that matches your situation.

Requirements, codes and thresholds here are based on Google's official help pages as of November 2026. Google updates these policies, so confirm the details on the linked pages before making changes.

First, figure out which side of the problem you're on

"Gmail isn't delivering my email" can mean two very different problems. Find your row and skip to the matching section.

If you check everything on the receiving side and still find nothing, the problem is probably with the sender, and the second half of this article is what they need to read.

Not receiving email in your Gmail inbox: what to check

Google's own checklist for this is the help page Gmail messages are missing. The steps below follow it. Do them in Gmail on a computer, in a browser: it's easier to see your settings there, and it rules out problems with phone apps or other mail clients.

1. Search Spam and Trash too. In the search bar, open Show search options, change the dropdown next to "Search" to Mail & Spam & Trash, and search for the sender's address or a word from the subject. Normal searches skip Spam and Trash, and messages there are permanently deleted after 30 days. If you find the email in Spam, open it and select Not spam.
2. Check the other inbox tabs. With the Default inbox type, Gmail sorts mail into Primary, Social, Promotions, Updates and Forums. Receipts, newsletters and account notices often land in Promotions or Updates. Dragging a message onto the Primary tab moves it and helps Gmail learn where similar mail should go.
3. Look for filters and blocked senders. Go to Settings (gear icon) > See all settings > Filters and Blocked Addresses. Any filter that says "Delete it" or "Skip Inbox" can make mail seem to vanish; edit or delete it. Mail from a blocked sender goes straight to Spam, so if the sender is listed there, select it and click Unblock selected addresses.
4. Review forwarding and POP/IMAP. On the Forwarding and POP/IMAP tab, if you forward mail, choose Keep Gmail's copy in the Inbox. If you see a forwarding address you don't recognize, select Disable forwarding; unfamiliar forwarding can be a sign that someone else has access to your account, so also review Third-party apps & services in your Google Account and remove anything you don't recognize. If POP is set to delete or archive Gmail's copy, switch it to keep Gmail's copy in the inbox and save.
5. Check your storage. Every Google Account gets up to 15 GB of free storage, shared between Gmail, Google Drive and Google Photos. When it fills up, your ability to send and receive email in Gmail can be impacted. Free up space by deleting large files or old emails with big attachments.
6. Check other apps and devices. There is only one copy of each Gmail message, so deleting or archiving it in a synced app (Outlook, Apple Mail, a phone client) removes it from Gmail as well. Look for auto-delete or auto-archive rules in those apps.

Still missing? Rule out the sender's side

If none of that turns up the message, it probably never reached Gmail. Ask the sender a few questions:

• Did they get a bounce? A typo in your address returns 550 5.1.1, meaning the account doesn't exist. Have them check for misspellings, stray dots or spaces.
• Is your mailbox full? Senders see 452 4.2.2 when your inbox is out of storage. That's temporary. An account that is both full and inactive returns 552 5.2.2, which is permanent. Free up space, then ask them to resend.
• Is it just late? Codes starting with 4 are temporary deferrals. The sending server normally retries later, so the message can arrive with a delay rather than not at all.
• Is their domain authenticated? Gmail can send unauthenticated mail to spam or reject it outright. If the sender is a company or an online service, point them to the sender sections below.

On a Google Workspace (work or school) account, your administrator can use Email Log Search to trace messages, so start there.

Gmail blocking your emails: read the bounce code

When Gmail refuses a message, the sending server returns a bounce. If you sent from Gmail, it usually comes from "Mail Delivery Subsystem" with the subject "Delivery Status Notification (Failure)". Find the three-part code in it. 4.x.x means a temporary rejection; the sender's server will usually retry. 5.x.x means the message was refused permanently. A typical example:

550 5.7.26 This mail has been blocked because the sender is unauthenticated.

These are the codes you're most likely to see, taken from Google's Gmail SMTP errors and codes reference:

One more case if you send from a personal Gmail account: Gmail also limits sending to 500 emails a day or one email to more than 500 recipients. Going over it blocks sending for roughly 1 to 24 hours, and the limits differ by account type. It is a temporary block, not a reputation problem. For large mailings, Google suggests using a Google Group instead.

Gmail's sender requirements (in effect since February 2024)

Since February 2024, Google's Email sender guidelines apply to everyone who sends to personal Gmail accounts. All senders must:

• Set up SPF or DKIM for the sending domain
• Have valid forward and reverse DNS (PTR) for the sending IP, with the two matching
• Use TLS when transmitting email
• Keep the spam rate reported in Postmaster Tools below 0.3% (Google recommends staying under 0.1%)
• Format messages according to RFC 5322 and not impersonate Gmail From: headers

Bulk senders, meaning those sending roughly 5,000 or more messages a day to Gmail accounts, must also:

• Set up both SPF and DKIM
• Publish a DMARC record (a policy of p=none is acceptable)
• Align the From: domain with the SPF or DKIM domain
• Support one-click unsubscribe for marketing and subscribed messages, with a visible unsubscribe link in the body

The 5,000 count is per primary domain, so mail from subdomains adds up. Once you meet the criteria, Google treats you as a bulk sender permanently. According to Google's sender guidelines FAQ, Gmail started ramping up enforcement on non-compliant traffic in November 2025, which means temporary and permanent rejections or delivery to spam. The guidelines don't apply to messages sent to Google Workspace accounts, only to personal Gmail. Yahoo publishes closely matching requirements.

A minimal DNS setup looks like this (documentation values only):

example.com.                       TXT  "v=spf1 ip4:203.0.113.10 -all"
selector1._domainkey.example.com.  TXT  "v=DKIM1; k=rsa; p=(public key)"
_dmarc.example.com.                TXT  "v=DMARC1; p=none; rua=mailto:dmarc@example.com"
mail.example.com.                  A    203.0.113.10
10.113.0.203.in-addr.arpa.         PTR  mail.example.com.

DKIM keys need to be at least 1024 bits for personal Gmail; Google recommends 2048. For a step-by-step walkthrough, see how to set up SPF, DKIM and DMARC.

Emails going to spam or rejected: a step-by-step fix

Whether you're getting hard bounces or your emails are quietly going to spam, work through these steps in order.

1. Write down the exact bounce code. Match it against the table above to see whether you're dealing with authentication, TLS, volume or reputation. Don't guess; the code is the most specific clue you have.
2. Send a test message and read the headers. Send to a Gmail address you control, open the message in a browser, then choose More > Show original. In the authentication results, look for spf=pass, dkim=pass and dmarc=pass, and check that the domain in From: matches the domain that passed.
3. List every system that sends as your domain. Your own mail server, a newsletter platform, a CRM, website contact forms, invoicing tools. A common cause of failures is one service that was never added to SPF or never set up to sign with DKIM.
4. Check blacklists. Run your sending IP and domain through a blacklist (DNSBL) check. Gmail relies on its own reputation data, so a public listing isn't automatically the reason Gmail blocks you. But a listing often points to a compromised account, an open form being abused or a shared IP with bad neighbours, and it will hurt delivery to other providers. If you're listed, see what to do when email isn't delivered because of a blacklist.
5. Set up Postmaster Tools. Add your domain to Postmaster Tools (the DKIM d= domain or the SPF Return-Path domain) and verify it with the TXT or CNAME record it gives you. The dashboards show spam rate, authentication and delivery errors, and the Compliance status dashboard marks each sender requirement as Compliant or Needs work. Low-volume senders may see no data. Changes can take up to 7 days to show up.
6. Fix how you send, not just DNS. Only mail people who asked for it, confirm addresses at sign-up, process unsubscribes promptly, and consider dropping recipients who never open your mail. Google notes that the longer a high spam rate continues, the more likely future messages are to go to spam.
7. Ramp back up gradually. After fixing a problem, don't resend your entire backlog at once. A sudden spike is exactly what triggers rate limits such as 421 4.7.28.

Be realistic about timing. Correct DNS takes effect quickly, but a damaged reputation recovers only as Gmail sees consistently clean mail from you, and nobody can promise that by a particular date.

FAQ

Official pages used

The facts in this article were checked against the official pages below at the time of publication. Policies and behavior change without notice, so check the official pages before relying on anything important.

• Email sender guidelines (Google Workspace Admin Help)
• Email sender guidelines FAQ (Google Workspace Admin Help)
• Gmail SMTP errors and codes
• Gmail messages are missing (Gmail Help)
• Postmaster Tools dashboards (Gmail Help)
• Set up Postmaster Tools (Gmail Help)
• Emails that bounce or are rejected (Gmail Help)
• Inbox categories and tabs (Gmail Help)
• Block or unblock a sender (Gmail Help)
• Google Account storage (Google One Help)
• Trace an email with its full header (Gmail Help)
• Sender Best Practices (Yahoo Sender Hub)

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