What is cold email deliverability?
Deliverability is whether your emails reach the inbox, rather than the spam folder or nowhere at all. For cold email it decides everything: if prospects never see your message, the copy, the offer and the targeting don’t matter.
Email providers decide where your messages land based on who you are (is your domain set up properly?), how you behave (how much you send and how fast) and how people react (do they reply, or mark you as spam?).
1. Use separate sending domains
Many B2B teams send cold email from domains that are similar to, but separate from, their main company domain (for example, a variation of the company name). If something goes wrong, the main domain that your team uses for everyday email and client work stays protected.
Each sending domain should point visitors to your main website, look like a real business and be set up properly before it sends a single email.
2. Set up SPF, DKIM and DMARC
These three records prove to email providers that your emails really come from you:
SPF
lists the servers allowed to send email for your domain.
DKIM
adds a digital signature to each email. Google recommends a key of at least 1024 bits, with 2048 bits preferred.
DMARC
tells providers what to do with emails that fail those checks.
Google’s Email sender guidelines require everyone sending to personal Gmail accounts to set up SPF or DKIM, and anyone sending more than 5,000 messages a day to Gmail accounts to set up SPF, DKIM and DMARC. Even if you send far fewer, setting up all three is the safe choice.
3. Warm up new inboxes slowly
A brand-new inbox that suddenly sends hundreds of emails looks like spam. Start with a small number of emails each day and increase slowly over several weeks. Google’s guidelines advise increasing sending volume slowly and watching for problems as you go.
4. Keep your list clean
Sending to addresses that don’t exist (bounces) is one of the fastest ways to damage your sender reputation. Before any campaign:
- Check every address is valid
- Remove role addresses like info@ unless they’re the right contact
- Never buy email lists. Google’s guidelines say not to purchase email addresses from other companies.
Hand-built lists aimed at your Ideal Prospect Profile help here too: fewer, better contacts means fewer bounces and fewer spam complaints.
5. Send at a sensible pace, and write like a person
Spread your sending
Keep the number of emails per inbox per day modest, and add more inboxes rather than pushing one inbox harder.
Keep it short and plain
Short emails with few or no images and links look like normal business email.
Make opting out easy
Tell people how to stop hearing from you, include your business address, and honour every request quickly. Every cold email shows a postal address and a clear way to opt out.
Aim for replies
A question people want to answer helps more than any trick.
6. Watch your spam rate and fix problems early
Google’s guidelines ask senders to keep the spam rate reported in Google’s Postmaster Tools below 0.3%, and recommend keeping it below 0.1%. Watch bounce rates and replies too. If they change suddenly, pause and find out why before sending more.
Google also notes that it doesn’t track open rates, so judge campaigns on replies and meetings, not opens.
Pre-send checklist
Before every campaign, check:
- Sending domains are separate from your main domain and redirect to your website
- SPF, DKIM and DMARC pass for every sending domain
- Inboxes have been warmed up
- Every address on the list has been checked
- Daily volumes per inbox are within safe limits
- Every email has an easy opt-out and your business address
- Spam and bounce rates from the last campaign are low
How RocketFuel handles deliverability
Deliverability is part of every cold email campaign we run, as part of our wider outbound lead generation service.
Our set-up: we warm up every mailbox for 2 weeks before a campaign starts, and each mailbox sends up to 30 emails a day.
Wondering whether email or LinkedIn should come first? Read cold email vs LinkedIn outreach.