The email deliverability guide for B2B SaaS teams

Why deliverability decides your results

Deliverability is the share of your email that reaches the inbox instead of spam or a bounce. Nothing else in outbound matters if this number is poor, and once a domain’s reputation slips, it takes weeks to recover. Worse, a poor reputation on your primary domain affects onboarding emails, invoices and password resets for every customer.

This guide covers the technical setup, the operating rules, and how Kairev enforces them automatically.

Authentication: SPF, DKIM and DMARC

Receivers check three DNS records before they trust a message.

Record	What it proves	Kairev’s requirement
SPF	The sending server is allowed to send for the domain	Present on the sending domain and its return path
DKIM	The message was signed by the domain and not altered	Selector published for the sending domain
DMARC	What to do when SPF or DKIM fail, and where to send reports	Policy published, aligned with the From domain

Kairev runs an alignment check against the sending domain before it sends and will refuse to send when a required record is missing. You can turn the gate on in Settings so that no message goes out unaligned.

Use separate sending domains

Cold outreach should never come from the domain your customers know. Register one or two look-alike domains (for example a .co or a get- prefix), point their websites to your main site, set up authentication on them, and create your sending inboxes there.

• Your main domain's reputation is protected whatever happens.
• You can rotate or retire a sending domain without touching production email.
• Replies still land where your team reads them, because the agent handles them.

Kairev blocks cold outreach from the primary domain entirely. This is not an option you can switch off.

Warm up before you scale

A brand-new inbox that sends 50 cold emails on day one looks exactly like a spammer. Warm-up means starting small and ramping while the inbox earns a reputation.

Kairev’s default ramp starts at 5 emails a day for a new inbox and grows to a ceiling of 30 a day over 21 days. The ceiling is adjustable between 5 and 50 per inbox, and the total number of new prospects contacted per workspace is capped at 100 a day by default.

Watch bounces and complaints, and stop early

Two signals matter most. Bounces tell you the list is stale. Spam complaints tell you the message or the targeting is wrong.

• Bounce rate above 3% on a rolling window of 200 sends.
• Spam complaint rate above 0.1%.
• A sudden drop in reply rate on an inbox that was performing.

When either threshold is crossed, Kairev pauses the affected inbox, writes an audit entry, notifies the workspace Owner and Desk Lead, and shows a diagnosis such as “12 bounces from list X, likely stale data” with resume options. Nothing else keeps sending in the background.

Make unsubscribing effortless

Every cold email needs a working one-click unsubscribe and a postal address. Suppression must be honoured everywhere: if a contact unsubscribes from a sales sequence, the marketing Desk must not email them either. Kairev keeps a single suppression list shared by every Desk.

Consent rules by country

Some jurisdictions require consent or an existing relationship before a business email may be sent. Kairev blocks cold outreach to recipients in those countries unless consent is recorded on the contact, and administrators can add countries to the list but cannot remove the legally required ones.

Content that stays out of spam

• Plain, personal, short. One idea, one ask.
• No misleading subject lines and no fake reply threads.
• Few links, no tracking-heavy templates, no attachments in a first email.
• Vary wording between contacts. Near-identical messages sent in bulk are a spam signal, and Kairev’s duplication check parks them.

A weekly deliverability review

1. Bounce and complaint rate per inbox.
2. Reply and positive reply rate per sequence.
3. Any auto-pause events and what caused them.
4. DMARC aggregate reports for unexpected senders.

Ten minutes a week is enough when the system enforces the rules for you.

FAQs

Can I use my Google Workspace inbox for cold email?

You can connect it for replies and support, but Kairev will not send cold outreach from it. Use warmed inboxes on separate sending domains instead.

What happens to a paused inbox?

It stays paused until someone with Owner, Admin or Desk Lead rights reviews the diagnosis and resumes it. Kairev never resumes on its own.

Where do DMARC reports go?

Point the report address in your DMARC record at an inbox your team reads. Kairev's Support Desk can be that inbox.