Cold email deliverability: how to stay out of spam
Short answer
Cold email stays out of spam when the sending domain is authenticated (SPF, DKIM and DMARC), each mailbox is warmed up gradually and kept to a low daily volume, every address is verified before sending, and the emails are relevant enough that people reply instead of marking them as spam.
Why cold email lands in spam
Mailbox providers judge every message by the reputation of the domain and mailbox it comes from. Reputation drops when a mailbox suddenly sends far more than it used to, when many messages bounce, and when recipients mark mail as spam. Most deliverability problems are one of those three, caused by sending too much, too fast, to unverified lists.
Authenticate the domain
SPF, DKIM and DMARC records tell receiving servers that your mail is really yours. Without them, even perfectly written email is treated with suspicion. They are a one-time DNS setup and are the first thing to check when deliverability drops.
Warm up and keep daily volume low
A new mailbox has no reputation. Start with a handful of emails a day and increase slowly over a few weeks. A fully warmed mailbox sustains roughly 20 to 35 cold emails a day; well under 10 is appropriate in the first weeks. If you need more volume, add mailboxes rather than pushing one harder.
Pipestork ramps each new mailbox from 5 to 35 emails a day over about 18 days and spreads sending across the recipient's local business hours.
Only send to verified addresses
Bounces are one of the fastest ways to damage a domain. Verify every address before it is used; an address that cannot be verified should not be emailed at all. Pipestork verifies every contact and never sends to an address that failed verification, which it also does not charge for.
Write emails people answer
Engagement is a deliverability signal. Short, plain-text emails with a specific reason and a simple question get replies; template blasts with images, tracking-heavy links and attachments get ignored or reported. Relevance is the best long-term protection a domain has.
Protect your main domain
Some teams send cold email from separate lookalike domains, so any reputation damage never touches the domain used for invoices and customer mail. Pipestork supports sending from your own mailbox with conservative limits, and offers managed lookalike domains, registered and warmed for you, by invitation.
Have the agents do this for you
Pipestork researches your market from your website, finds verified decision-makers, writes a sequence per prospect and sends it with conservative limits, so you can apply everything on this page without doing it by hand.
Try it with $30 in credits →