How to Improve Email Deliverability in UniLink (Get Out of Spam and Into the Inbox)

A practical guide to DNS authentication, custom sending domains, list hygiene, and everything else that determines whether your emails land in the inbox or disappear into spam.

You can write the most compelling email in the world, and it will have zero impact if it never reaches the inbox. Email deliverability — the ability to land in the primary inbox rather than the spam folder or promotions tab — is determined by a combination of technical authentication, sender reputation, and list quality. Most senders who struggle with deliverability are missing one or more of the technical foundations. This guide explains each factor clearly and shows you how to configure them in UniLink.

What Email Deliverability Means

Deliverability is not the same as delivery rate. Delivery rate tells you how many emails were accepted by the recipient's mail server (i.e., did not bounce). Deliverability tells you where those accepted emails ended up — primary inbox, spam folder, or promotions tab. An email can be "delivered" and still go completely unread in the spam folder.

Inbox providers like Gmail, Outlook, and Apple Mail use a combination of signals to decide where to route incoming email. These signals include whether your domain has valid SPF, DKIM, and DMARC records; your historical sending reputation (spam complaint rate, bounce rate, engagement rate); and the content of the email itself (certain words, link patterns, and HTML structures that match known spam templates).

When multiple signals suggest low trust, inbox providers route your email to spam or block it entirely. Fixing deliverability means addressing each of these signals systematically — starting with authentication, because it is the foundation everything else rests on.

How to Get Started With Email Deliverability in UniLink

1. Add a custom sending domain — navigate to Email → Settings → Sending Domain in your UniLink dashboard. Enter your domain name (e.g., yourcompany.com) and UniLink will generate the DNS records you need to add.
2. Add the SPF record to your DNS — SPF (Sender Policy Framework) authorises UniLink's mail servers to send on behalf of your domain. UniLink provides the exact TXT record value. Add it to your domain's DNS through your registrar (e.g., Namecheap, Cloudflare, GoDaddy). If an SPF record already exists, merge the UniLink include statement into it rather than creating a duplicate.
3. Add the DKIM record to your DNS — DKIM (DomainKeys Identified Mail) adds a cryptographic signature to each outgoing email. UniLink provides a CNAME or TXT record containing the public key. Add this record to your DNS exactly as shown — do not alter the value.
4. Add or verify a DMARC policy — DMARC tells inbox providers what to do when an email fails SPF or DKIM. A basic policy (v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com) is sufficient to start. Once you confirm authentication is working correctly, tighten the policy to p=quarantine or p=reject.
5. Verify authentication in UniLink — after adding the DNS records, return to Email → Settings → Sending Domain and click Verify. UniLink checks all three records and shows a green status for each one that passes. DNS propagation can take up to 48 hours, so check again if verification fails immediately.
6. Send a test email — use UniLink's Send Test function to send a message to a personal Gmail or Outlook inbox. Check whether it arrives in the primary tab and inspect the email headers to confirm SPF and DKIM both show "pass".
7. Monitor your bounce and complaint rates — after each campaign, check Email → Analytics for bounce rate and unsubscribe rate. Keep hard bounce rate below 2% and spam complaint rate below 0.1% to maintain a healthy sender reputation.

How to Warm Up a New Sending Domain

1. Start with your most engaged contacts — when sending from a brand new domain, inbox providers have no historical reputation to reference. Begin by emailing only subscribers who have recently engaged with you (opened or clicked in the last 30 days).
2. Increase volume gradually over weeks — a typical warm-up schedule starts at 50 emails per day in week one, doubles each week, and reaches full volume after four to six weeks. Sudden spikes from a new domain are a strong spam signal.
3. Send consistently, not sporadically — irregular sending patterns (nothing for two weeks, then 5,000 emails at once) harm reputation. Set a predictable sending cadence, even if individual send volumes are small during warm-up.
4. Monitor engagement closely during warm-up — if open rates drop below 15% or spam complaints appear during the warm-up period, pause and investigate before continuing. A problem caught at 200 sends is much easier to fix than one caught at 20,000.
5. Avoid purchased or scraped lists during warm-up — new domains are especially vulnerable to reputation damage from cold outreach to unengaged or invalid addresses. Use only opted-in contacts during the warm-up phase.

Key Settings Explained

How to Get the Most Out of Email Deliverability

Authentication is necessary but not sufficient. Once your technical foundation is in place, the ongoing work of deliverability is about maintaining a clean list and sending emails people actually want to receive. Inbox providers increasingly factor engagement signals — opens, clicks, replies, and moves out of spam — into routing decisions. A technically perfect email from a domain with poor engagement history will still end up in the spam folder.

List hygiene is the most impactful ongoing practice. Every time you send to addresses that bounce, every time a subscriber marks your email as spam, your sender reputation takes a small hit. Those hits accumulate. Removing hard bounces immediately after each campaign (UniLink does this automatically), and suppressing addresses with multiple soft bounces, keeps your reputation from eroding over time.

Content also matters. Certain words and phrases — "free money", "click now", "you're a winner", excessive dollar signs — are associated with spam templates and will raise your spam score even if your authentication is perfect. UniLink's campaign preview includes a spam score check that flags risky words before you send. Use it before every campaign.

Finally, make it easy to unsubscribe. This seems counterintuitive, but a clear unsubscribe link reduces spam complaints dramatically. A subscriber who cannot find the unsubscribe button will hit "report spam" instead — and that complaint hurts your deliverability far more than losing a subscriber.

Troubleshooting Common Issues