Do hyperlinks always reduce deliverability?

At some point, someone told you that links hurt deliverability. So you started trimming them, maybe avoiding them altogether. And now your emails look a bit sparse and your CTR has suffered. Here's the truth: links don't hurt deliverability. Bad links do.

Spam filters don't punish you for including links. They evaluate the links you include. There's a real difference. A well-placed link to your product page or a helpful article is completely normal. Filters expect it. What they flag is something else entirely.

The things that actually raise red flags:

• Links to suspicious or newly registered domains. If the destination domain is less than a few weeks old, has a history of phishing reports, or shows up on URL filtering lists like those maintained by Spamhaus, the filter notices. It doesn't matter how clean the rest of your email is.
• Mismatched anchor text. If your link says "Click here to unsubscribe" but points to a totally unrelated domain, that's a red flag. The text and the destination should make sense together.
• Shortened or redirected URLs that obscure the destination. Bit.ly links and heavy redirect chains were heavily abused by spammers. Some filters still treat them with suspicion, especially in bulk email.
• An unusual number of links for the context. There's no magic number, but 3 to 5 links in a standard marketing email is completely fine. A plain-text cold email with 12 links looks odd. The ratio of links to content is what gets evaluated, not an absolute count.

So how many links should you include? Enough to serve the reader, no more. If you're sending a newsletter, a few links to articles or products fit naturally. If you're sending a transactional email, one or two action links make sense. Stuffing an email with links just to fill space will hurt engagement, and low engagement is what actually tanks your sender reputation over time.

One thing worth double-checking: if you use link tracking through your ESP, make sure the tracking domain is properly set up and has a good reputation of its own. A tracking subdomain that hasn't been configured correctly can look suspicious even if your destination URLs are perfectly fine. Most major ESPs like Mailchimp or Klaviyo handle this automatically, but it's worth confirming if you've set up custom click tracking.

The short version: link to things that are relevant, link to domains you trust, and don't obsess over the count. If you're worried your emails might be triggering spam filters for other reasons, our free Email Header Analyzer can help you spot what's actually going on.