Cold email deliverability in Singapore (2026)

Most cold campaigns do not fail because the copy is bad. They fail because the email never reaches the inbox. For teams selling across Singapore and the wider APAC region, deliverability is the single biggest lever you control, and it is mostly about boring infrastructure done correctly.

Start with domain authentication

Before you send a single cold email, your sending domain needs three records in place. Without them, providers like Gmail and Outlook treat your mail as suspicious by default.

• SPF: tells receiving servers which hosts are allowed to send for your domain.
• DKIM: cryptographically signs your mail so it cannot be silently spoofed.
• DMARC: tells receivers what to do when SPF or DKIM fail, and gives you reporting.

SPF, DKIM and DMARC in plain English

SPF (Sender Policy Framework) is a list, published in your domain's DNS, of the mail servers allowed to send for you. When a receiving server gets your email, it checks whether the sending server is on that list, so if you send through Google Workspace, Microsoft 365 or an email tool, their servers belong in your SPF record.

DKIM (DomainKeys Identified Mail) attaches a cryptographic signature to every email, tied to a key published in your DNS. The receiving server uses it to confirm the message really came from your domain and was not changed on the way. Your mailbox provider generates the key, and you publish the matching record.

DMARC ties the two together. It tells receivers what to do when a message fails SPF or DKIM, whether to do nothing, quarantine it or reject it, and it sends you reports on who is sending with your domain, which surfaces both misconfigurations and impersonation. Even a monitoring-only DMARC policy shows providers you take authentication seriously.

• Publish an SPF record that includes every service you send through.
• Turn on DKIM signing in your mailbox provider and publish the key.
• Add a DMARC record, starting with a monitoring policy, then tighten it.
• Check all three with a free checker before your first campaign.

A common APAC mistake is sending cold campaigns from your primary domain. Use a separate sending domain or subdomain so a reputation dip never touches the address your customers reply to.

Warm up before you scale

A brand-new mailbox that suddenly sends 300 emails a day looks exactly like a spam run. Ramp gradually. Start at a low daily floor, increase only when bounce and complaint rates stay healthy, and let genuine replies build positive signal.

How long does warmup take? There is no single number, but a useful rule of thumb is two to four weeks for a brand-new domain or mailbox before you push real volume, raising the daily limit a little each day rather than in one jump. An established mailbox that already sends normal business email needs less; the newer the domain, the slower you should go.

• Start low: a new domain might begin at a handful of sends a day, not fifty.
• Increase gradually, never in one leap.
• Keep your list clean, because bounces hurt reputation fast.
• Spread volume across several mailboxes rather than overloading one.

On paid plans, HuntSales runs a warm-up ramp on each connected mailbox: switch it on, set the starting floor and the daily increase, and it raises the mailbox's daily limit for you.

Sender reputation is earned in weeks and lost in a single bad afternoon. Ramp slowly, then protect it.

Watch the signals that matter

Open rates are a vanity metric now that providers pre-fetch images. The signals that actually predict inbox placement are reply rate, bounce rate, and spam-complaint rate. Keep bounces low by verifying emails before sending, and stop a sequence the moment a prospect replies so they never get a redundant follow-up.

Bring your own provider

Shared sending infrastructure means your deliverability rides on strangers' behaviour. Sending from your own mailbox or your own ESP keeps reputation on your domain, where you control it. That is the model HuntSales is built around: connect Gmail, Outlook, or any SMTP mailbox, and your reputation stays yours.

Get these fundamentals right and your copy finally gets a fair hearing. Get them wrong and the best message in the world lands in spam.