Why are my emails going to spam? If you are asking that right now, you are not alone. In October 2026, about one email in four received by the inboxes Mailwarm monitors was filtered to spam.
Here is the short answer. Emails land in spam when mailbox providers cannot verify who sent them, or do not trust the sender's reputation yet. So you check five things: authentication, blocklists, reputation, sending volume, and your content and list.
Check one. Authentication. Your domain needs three DNS records. SPF lists the servers allowed to send for you. DKIM signs every email so it cannot be changed on the way. And DMARC tells Gmail and Outlook what to do when a check fails. Here are the live records of mailwarm.com. SPF, DKIM and DMARC are all published, and DMARC is set to quarantine. In our network study of almost 13,000 sending domains, one in four had no DMARC record at all. Gmail requires all three for bulk senders, so start here.
Check two. Blocklists. If your domain or sending IP is listed on a blocklist like Spamhaus or Barracuda, many filters will reject or bury your email. In the same study, 8.4% of domains were listed on at least one blocklist. Check your domain and IP, and if you are listed, fix the cause before you request removal.
Check three. Reputation. Open Google Postmaster Tools and look at your spam rate. Google asks senders to stay below 0.1%, and never reach 0.3%. Above that line, too many recipients are marking your emails as spam, and filters react fast.
Check four. Volume. A new domain that jumps from zero to 500 emails a day looks exactly like a spammer. Ramp up slowly, over two to four weeks, while real people open and reply. That is what email warmup does. Mailwarm is an email warmup and deliverability monitoring tool, built by a Y Combinator team since 2020. If you are looking for the best email warmup tool, check for three things: real inbox engagement, live inbox and spam placement tracking, and a deliverability expert you can talk to. Mailwarm includes all three in every plan.
Check five. Content and list. Remove addresses that bounce, avoid link shorteners and heavy images, and send plain text when you can. A clean list protects your reputation more than any subject line trick.
Quick recap: authentication, blocklists, reputation, volume, content. To test three of them in one minute, use the free email deliverability test on mailwarm.com. Send one email to the test address, and you get a score out of 100 with a ranked fix list. The link is in the description.
