Email infrastructure

Email deliverability is the percentage of your sent emails that reach the recipient's primary inbox — not spam, not bounced, not blocked. A healthy inbox placement rate is above 95%. For outbound teams it directly drives pipeline: if your emails don't land, your sequences produce zero replies regardless of messaging. Poor deliverability also compounds, as each bounce or complaint further damages your sender reputation. Key factors:

• Authentication — SPF, DKIM, and DMARC records that verify your identity
• Sender reputation — a score based on bounces, complaints, and engagement
• Sending behavior — volume consistency, warm-up, and list hygiene

See the full breakdown in our deliverability glossary.

Email deliverability is the outcome — did your email land in the primary inbox? Sender reputation is one of the inputs that determines it. Think of reputation as your domain's credit score: built over time from bounce rates, spam complaints, engagement, and volume consistency. High reputation means Google and Outlook trust your domain — but reputation alone isn't enough; you also need correct authentication and clean sending. Learn how to improve both in our deliverability guide.

Email warm-up gradually builds trust with inbox providers on a new domain or mailbox before sending at full volume. A brand-new domain has no sending history, so sending high volume immediately triggers spam filters. It runs in phases:

• Days 1–7 — low volume, mostly within a warm-up network that generates positive engagement
• Days 8–14 — volume increases as the domain earns reputation
• Weeks 3–4 — the mailbox reaches full capacity with a healthy reputation

A solid warm-up takes 2–4 weeks. Rushing it is the fastest way to a blocklist — see safe sending limits.

The biggest mistakes share one root cause: treating email infrastructure as an afterthought. The most damaging ones:

• Sending from your primary domain — a reputation drop drags down your whole company's email
• Skipping warm-up — launching at full volume on a cold domain triggers filters immediately
• Dirty data — high bounce rates from unverified emails wreck sender reputation
• Missing authentication — no SPF, DKIM, or DMARC makes you easy to flag
• No monitoring — damage goes undetected until reply rates collapse

All are preventable with the right setup and verified data sources.

Topo provides a zero-touch deliverability setup — it handles the technical infrastructure so your team doesn't manage domains, DNS, or warm-up manually. Topo configures:

• Secondary domains — dedicated outbound domains that isolate sales sending from your primary domain
• DNS and authentication — SPF, DKIM, and DMARC set up automatically per domain
• Strategic clustering — mailboxes distributed across domains to limit accounts per domain
• Automated warm-up — every new mailbox joins Topo's private warm-up network before any prospect email is sent

So your AI sales agent starts on healthy infrastructure from day one.

Yes. Topo runs bi-weekly spam tests across all active mailboxes and automatically adjusts sending volumes based on the results. If a mailbox shows early signs of reputation decline, Topo throttles its volume down before damage compounds; when scores recover, volume ramps back up. This monitoring loop runs continuously without manual intervention, keeping every mailbox in a healthy range so your sequences maintain consistent inbox placement.