# Cold email glossary | GTM and Outreach

Source: https://exntra.in/glossary

# Cold email glossary

The words you'll meet in cold email, explained in one or two plain sentences.

Bounce

An email that couldn't be delivered. A hard bounce means the address doesn't exist; a soft bounce is temporary, like a full mailbox. Keep bounces under 2%.

Bounce rate

The share of your emails that bounced. High bounce rates tell providers your list is poor.

Cold email

A one-to-one business email to someone you haven't emailed before, with a clear, relevant reason to contact them.

DKIM

A digital signature on every email that proves it came from your domain and wasn't changed. [Learn more](/guides/spf-dkim-dmarc)

DMARC

A DNS record that tells inboxes what to do when SPF or DKIM fails, and sends you reports. Required by Google and Yahoo for bulk senders. [Learn more](/guides/spf-dkim-dmarc)

Email sequence

A series of emails sent to the same person a few days apart, stopping when they reply.

ESP

Email service provider: who hosts an inbox, such as Google Workspace, Microsoft 365, Zoho or Yahoo.

ESP matching

Sending to each lead from a mailbox on the same provider, for example Gmail leads from your Google mailbox. [Learn more](/product/campaigns)

ESP sending

Choosing which providers a campaign emails, for example only Microsoft leads. [Learn more](/product/campaigns)

Inbox placement

Whether your email lands in the inbox, the spam folder or a promotions tab.

MCP

Model Context Protocol: a standard way for AI assistants like Claude to use tools, such as launching a campaign. [Learn more](/api/mcp)

Machine open

An 'open' caused by software, such as Apple Mail pre-loading images or a security scanner checking links. Not a sign of interest. [Learn more](/product/analytics)

Personalisation variable

A placeholder like {{first\_name}} that's replaced with each lead's details.

Reply rate

The share of people who replied. The number that matters most in cold email.

Role address

A shared team address like info@ or sales@. Low reply rates and more spam reports.

Slow start

Sending few emails from a new mailbox at first, and raising the volume over a few weeks. [Learn more](/product/deliverability)

Smart scheduling

Spreading each mailbox's daily emails across the working day with random gaps, instead of sending in bursts. [Learn more](/product/campaigns)

Spam complaint rate

The share of recipients who mark your email as spam. Keep it under 0.1%; Google's limit is 0.3%.

SPF

A DNS record listing the servers allowed to send email for your domain. [Learn more](/guides/spf-dkim-dmarc)

Spintax

Alternative wordings like {Hi|Hey|Hello}, so each lead gets a slightly different email.

Throwaway inbox

A temporary address from a disposable email service. Nobody reads it.

Warm-up

Using a network of mailboxes that email each other and fake engagement to build reputation. Now risky: see why we don't do it. [Learn more](/guides/why-no-warmup)

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