Outbound has an unusual amount of jargon for a discipline that amounts to contacting strangers. Some of it is genuinely technical, some is vendor invention, and a fair amount is the same idea with three names.
This is everything you are likely to meet, grouped by where you will meet it. Use the headings to jump.
Deliverability and authentication
SPF (Sender Policy Framework) — A DNS record listing which servers may send mail on behalf of your domain. Receiving servers check it. A common failure is exceeding the ten-lookup limit, which causes the record to fail silently.
DKIM (DomainKeys Identified Mail) — A cryptographic signature added to outgoing mail, verified against a public key in your DNS. Proves the message was not altered in transit. Use 2048-bit keys.
DMARC — A policy record telling receivers what to do when SPF or DKIM fails: nothing (p=none), quarantine, or reject. Also requests reports. Effectively mandatory since Gmail and Yahoo’s bulk sender requirements.
MX record — DNS record specifying which server receives mail for a domain. Needed for replies to arrive.
Alignment — Whether the domain in the visible From address matches the domain that passed SPF or DKIM. DMARC requires alignment, not just a pass.
Sender reputation — A score inbox providers assign to your domain and IP based on sending behaviour, complaints, bounces and recipient engagement. Not published, inferred from placement.
Domain reputation — Reputation attached to the sending domain. Carries more weight than IP reputation for most senders and does not transfer to a new domain.
IP reputation — Reputation attached to the sending IP address. Matters most at high, consistent volume.
Shared IP — A sending IP used by multiple senders. Placement moves with everyone else’s behaviour. Quality depends entirely on whether the pool is vetted and monitored.
Dedicated IP — An IP used by one sender. Gives isolation and debuggability, but needs roughly 1,500 to 2,000 sends a month to build reputation, below which it underperforms a well-managed pool.
Warmup — Building sending history on a new mailbox or domain by exchanging mail through a network before contacting real prospects. Three to four weeks minimum.
Ramp — Gradually increasing daily sending volume rather than jumping to target. Typically 30% increases every two to three days.
Inbox placement — Where mail actually lands: Primary, Promotions, Updates or Spam. Distinct from delivery.
Delivery rate — Whether the receiving server accepted the message. Says nothing about which folder it went to.
Inbox placement test (seed test) — Sending to a set of test addresses across providers to see where mail lands. The only reliable way to know your placement.
Hard bounce — Permanent delivery failure, usually a non-existent address. Damages reputation quickly. Keep under 2%.
Soft bounce — Temporary failure: full mailbox, server unavailable. Less damaging but worth watching if persistent.
Complaint rate — Proportion of recipients marking mail as spam. The metric providers weight most heavily. Keep below 0.1%.
Blocklist (blacklist) — A published list of IPs or domains associated with spam. Being listed affects placement until delisted.
Spam trap — An address that exists only to catch senders using poor list practices. Hitting one is a strong negative signal.
Catch-all domain — A domain accepting mail to any address. Verification tools cannot confirm whether a specific address exists, so these are risky to send to.
Tracking domain — The domain used for click tracking and redirects. Should be custom and SSL-secured; shared tracking domains carry every other customer’s reputation.
Domain masking — Serving tracking links from an outreach domain so your primary website never appears in cold email headers.
Sender rotation — Distributing a campaign across multiple mailboxes so no single one carries all the volume.
Mailbox-to-domain ratio — How many mailboxes sit on one domain. Three is the working number; five is the practical ceiling.
Data and prospecting
ICP (Ideal Customer Profile) — A written definition of the company you sell to best: industry, size, geography, and qualifying attributes. Distinct from a persona, which describes a person.
Persona — The role you contact within an ICP account. A company is the ICP; the VP of Ops is the persona.
TAM / SAM / SOM — Total, serviceable and obtainable market. Mostly used in fundraising, occasionally useful for sizing a prospecting universe.
Lead — A contact record. Not a qualified opportunity, though the words get used interchangeably.
Prospect — A lead you have decided to contact.
Enrichment — Adding data to a record you already have: job title, company size, technologies, phone number.
Waterfall enrichment — Querying multiple data providers in sequence until one returns a match, to raise coverage above any single source.
Verification — Confirming an email address exists and accepts mail, before sending. The single most effective way to control bounce rate.
Match rate — The proportion of records a data provider can return information for. Varies enormously by region and seniority.
Direct dial — A phone number reaching a person’s desk without a switchboard.
Mobile number — A personal mobile. Connects far better than a switchboard and costs more to source.
Suppression list — Contacts who must not be contacted: unsubscribes, current customers, competitors, do-not-contact requests.
Do-not-contact (DNC) — Regulatory or self-maintained lists of people who must not be called or emailed.
Buying signal — An observable event suggesting a company or person may be in market: a job change, a hiring surge, funding, technology adoption, engagement with relevant content.
Intent data — Behavioural data suggesting research activity, typically from third-party content consumption. Broader and noisier than a direct signal.
Lookalike — A company resembling your existing customers on defined attributes, used to expand a target list.
ICP score — A numeric fit score applied to a lead before enrolment, used to gate who enters a sequence.
Sequencing and outreach
Sequence (cadence) — A planned series of touches over time across one or more channels.
Touch — A single contact attempt: an email, a connection request, a call, a message.
Multichannel — Using more than one channel in the same sequence, typically email and LinkedIn, increasingly with phone and WhatsApp.
Conditional branching — Sequence logic that changes the next step based on what happened: opened, replied, connected, answered.
Opener (ice-breaker) — The first line of a cold email, usually the personalised part.
Break-up email — A final message signalling you will stop following up. Frequently the highest-reply message in a sequence.
Bump — A short follow-up replying to your own previous email to raise it in the inbox.
Spintax — Syntax allowing randomised word variation across sends, so messages are not byte-identical.
Merge field (variable) — A placeholder replaced with lead data at send time. Always needs a fallback.
Fallback — The default value used when a merge field has no data. Without one, a merge failure produces visible broken text.
A/B test — Running two variants with one variable changed to see which performs better. One variable at a time, or the result means nothing.
Reply rate — Replies divided by sends. The most reliable top-level outbound metric.
Open rate — Opens divided by delivered. Unreliable since privacy protections began pre-fetching images, and should not be used for decisions.
Positive reply rate — Replies indicating interest, as opposed to all replies. Far more useful than raw reply rate.
Connection request — An invitation to connect. Weekly limits apply and are enforced at the account level.
InMail — A paid message to someone you are not connected to, available with Sales Navigator or Premium.
Open profile — A Premium setting allowing anyone to message the user without an InMail credit.
Sales Navigator — LinkedIn’s paid prospecting product with advanced filters and saved searches.
SSI (Social Selling Index) — LinkedIn’s own engagement score. Interesting, not actionable.
Withdrawal rate — Cancelling pending invitations that were never accepted. Keeping the pending queue small protects the acceptance ratio.
Engagement-first outreach — Reacting to or commenting on a prospect’s post before sending a connection request, so the name is familiar.
Post engager — Someone who reacted to or commented on a post. Commonly used as a warm prospecting source.
Rented profile (avatar) — An aged LinkedIn account with an existing network, operated on behalf of a company to scale outreach beyond its own accounts.
Sales and pipeline
SDR / BDR — Sales Development and Business Development Representative. Traditionally inbound and outbound respectively; now used interchangeably.
AE (Account Executive) — The person who runs the deal after qualification.
MQL / SQL — Marketing and Sales Qualified Lead. Definitions vary by company and are frequently a source of internal argument.
Meeting booked vs held — Whether a meeting was scheduled or actually took place. The distinction that decides what an agency guarantee is worth.
No-show rate — Booked meetings that did not happen. Commonly 20% to 40% on cold-sourced meetings.
Pipeline — Total value of open opportunities.
Cost per meeting — Total programme cost divided by meetings held. The metric worth comparing channels on.
Multi-threading — Contacting several people inside one target account rather than a single champion.
Missing something? The deliverability guide covers the technical terms in depth, and SPF, DKIM and DMARC explained goes further on authentication.