Do Short Links Hurt Email Deliverability?

Yes, the wrong ones do

Let's not bury this. Putting bit.ly or tinyurl links in your email campaigns measurably hurts deliverability. Postmark tested it and found URL shorteners hurt Gmail deliverability quite a bit, their words. Multiple ESPs now warn against shared shorteners outright, and plenty of senders have watched inbox placement recover after removing them.

This surprises people because short links feel tidy. Cleaner than a 200-character tagged URL, easier to read, trackable. All true. The problem isn't the shortness. It's whose domain the link lives on.

Shared domains, shared reputation

Spam filters score links by domain reputation. When you send from a shared shortener, your links live on a domain used by millions of strangers. Legitimate newsletters, sure. Also phishing campaigns, malware droppers and crypto scams, because free anonymous shorteners are the easiest cloaking tool on the internet.

Gmail can't tell your bit.ly link from a scammer's bit.ly link before resolving it. Same domain. So the domain's whole track record gets priced into your spam score. You're co-signing a loan with millions of people you've never met, and some of them are criminals.

It gets worse when the filter follows the link. A short link hides its destination by design, and mail providers treat that opacity itself as a risk signal. Redirect chains from a shared domain to your site look exactly like what attackers do.

The domain alignment problem

There's a second, quieter issue. Filters like it when the domains in your email agree with each other. You send from newsletter.acme.com, your links point at acme.com, everything lines up and the message looks coherent.

Now your links point at bit.ly instead. The sending domain and the link domains no longer match. That mismatch is another classic phishing pattern, because spoofed emails routinely pair a fake sender with unrelated link domains. You've made your legitimate email structurally resemble a fake one.

DMARC, SPF and DKIM authenticate your sending domain. None of it covers the domains your links point at. Alignment there is on you.

What to do instead

Option one: skip shortening in email entirely. Email clients render anchor text, not raw URLs. Your reader sees "View the spring collection," and the underlying URL can be as long and parameter-laden as you want. The 200-character tagged URL costs you nothing visually. This is the right answer for most newsletter links.

Option two: short links on your own branded domain. When you actually need compact URLs (plain-text emails, links people might copy around, print-adjacent stuff), use a shortener that runs on a domain you own. go.acme.com/spring instead of bit.ly/3xK9pQz.

A branded short domain fixes both problems at once. The reputation is yours alone, built by your sending behavior and nobody else's. And the domain aligns with your brand, so filters see coherence instead of mismatch. We covered the broader case for custom domains separately, but deliverability might be the single strongest argument on the list.

One honest caveat: a brand-new domain has no reputation at all, and no reputation is only slightly better than bad reputation. Warm it up. Send normally for a few weeks before you route a big campaign through it.

While you're in there, check your tracking

Two adjacent gotchas we see in email audits:

• Your ESP's click tracking is already a redirect. Mailchimp, Klaviyo and the rest wrap links in their own tracking domains. Add a shortener on top and you've built a redirect chain, and chains raise spam scores further. One redirect layer, maximum.
• Untagged email links dump into direct traffic. Every link in every campaign should carry UTMs, or your email attribution quietly leaks away. Tag the destination URL first, then shorten the tagged version. The UTM builder plus branded short links handles both steps in one place.

The test that settles it

Don't take anyone's word for this, including ours. Take your next campaign, split it, and send half with bit.ly links and half with either full URLs or your branded domain. Watch inbox placement and spam-folder rates per variant. Senders who run this test tend to run it exactly once, because the result is not subtle.

Generic shorteners were built for Twitter's 140-character era. Email in 2026 punishes them. Use your own domain or use no shortener at all.