A
- A2P messaging
- Application-to-person messaging: SMS sent by software rather than typed by a human. In the US it must be registered under 10DLC before carriers will deliver it reliably.
- Allowlist
- A list of senders a mailbox or organisation has explicitly chosen to accept. Being allowlisted by a recipient bypasses most filtering for that recipient only.
- A/B test
- Sending two variants of a message to comparable segments to see which performs better. Meaningful only when the sample is large enough that the difference is not noise.
B
- Blocklist
- A public or private list of domains and IPs known for abusive sending. Appearing on a major one collapses delivery until you are removed.
- Bounce rate
- The share of sent messages that could not be delivered. Hard bounces mean the address does not exist; soft bounces are temporary. Above roughly 3% hard bounces signals a list problem.
C
- Cadence
- The planned sequence of touches across channels and days that makes up an outbound campaign. Also called a sequence.
- Catch-all domain
- A domain that accepts mail to any address rather than rejecting unknown ones. Verification tools cannot confirm whether a specific mailbox exists, so these carry hidden bounce risk.
- Cold email
- An unsolicited email to someone with no prior relationship. Legal in most jurisdictions under conditions, but the conditions differ sharply between the US, UK and EU.
- Complaint rate
- The share of recipients who mark a message as spam. The single most damaging deliverability signal. Keep it under 0.1%; above 0.3% is critical.
- Compliance gate
- A pre-send checkpoint that verifies suppression status, registry listings, quiet hours, consent, template approval and volume limits before a message is dispatched.
- Connection request
- A LinkedIn invitation to connect. Rate-limited by LinkedIn, and automation that ignores those limits risks account restriction.
- Consent
- Permission to contact someone. Its form varies: explicit opt-in in the EU under GDPR, legitimate interest in some B2B contexts, and looser standards in the US.
- CRM
- Customer relationship management: the system of record for contacts, companies, deals and the history of interactions with each.
D
- Deal stage
- A named step in a pipeline representing how far an opportunity has progressed. Stages should reflect buyer behaviour, not internal activity.
- Deliverability
- Whether a message reaches the inbox rather than the spam folder or nowhere. Distinct from delivery, which only means the server accepted it.
- DKIM
- DomainKeys Identified Mail: a cryptographic signature proving a message was authorised by the domain owner and not altered in transit.
- DMARC
- A DNS policy tying SPF and DKIM together, telling receivers what to do when authentication fails and where to send reports.
- DNC registry
- A Do Not Call registry: a government list of numbers that must not receive marketing calls. Must be checked at dial time, not at import time.
- Domain reputation
- A mailbox provider's running score of your sending domain, built from volume, consistency, engagement and complaints.
- Double opt-in
- Requiring a recipient to confirm a subscription via a second action, usually an emailed link. The strongest form of consent evidence.
- Drip campaign
- A sequence of pre-scheduled messages sent at fixed intervals, usually triggered by an action rather than run as a batch.
E
- Enrichment
- Adding data to a contact record from external sources — job title, company size, technology used — so segmentation and personalisation can be more specific.
- Engagement rate
- How recipients interact with messages: opens, clicks, replies. Replies carry the most weight with mailbox providers because they are hardest to fake.
G
- GDPR
- The EU General Data Protection Regulation. Governs processing of personal data, requires a lawful basis for contact, and gives individuals rights over their data.
H
- Hard bounce
- A permanent delivery failure, usually because the address does not exist. Hard-bounced addresses must be suppressed immediately.
I
- ICP
- Ideal customer profile: a definition of the accounts most likely to buy and stay. Drives targeting, and a vague one is the root cause of most poor outbound results.
- Inbox placement
- Where a delivered message actually lands — primary inbox, promotions tab, or spam. Delivery rate does not measure this; only seed tests and engagement patterns hint at it.
- Intent data
- Signals suggesting an account is actively researching a purchase, such as content consumption or job postings. Useful for prioritisation, unreliable as sole justification for contact.
L
- Lead scoring
- Ranking contacts by likelihood to convert, using fit and behaviour. Only as good as the outcome data used to calibrate it.
- Legitimate interest
- A lawful basis under GDPR for processing data without explicit consent, subject to a balancing test. Frequently over-claimed in cold outbound.
- List hygiene
- The ongoing removal of invalid, bounced, unengaged and suppressed addresses. The cheapest deliverability intervention available.
M
- Mailbox provider
- The service delivering mail to the recipient — Gmail, Outlook, Yahoo. Each has its own filtering behaviour, so results vary by recipient mix.
- Multi-channel outbound
- Coordinated outreach across more than one channel — email, phone, LinkedIn, SMS, WhatsApp — with shared state and a shared opt-out.
O
- Open rate
- The share of recipients whose mail client loaded the tracking pixel. Increasingly unreliable due to privacy proxies that pre-load images.
- Opt-out
- A recipient's withdrawal of consent. Should suppress the person across every channel, not only the one they used to tell you.
P
- Pipeline
- The set of open opportunities and their stages. Pipeline coverage compares total open value against the target for a period.
Q
- Quality rating
- WhatsApp's per-number score derived from user blocks and reports. Green, yellow or red; sustained red reduces messaging limits.
- Quiet hours
- Times of day when contact is prohibited or inadvisable, evaluated in the recipient's timezone rather than yours.
R
S
- Seed test
- Sending a campaign to monitored mailboxes across providers to see where it lands. Catches breakage; does not measure real-world placement.
- Sender score
- A third-party reputation rating for a sending IP. Directional only, since the providers that matter use their own internal scoring.
- Sequence
- See cadence. A structured series of touches, usually with branching based on recipient behaviour.
- SPF
- Sender Policy Framework: a DNS record listing which servers may send mail for a domain.
- Suppression list
- The record of contacts who must not be contacted, covering opt-outs, hard bounces, complaints and manual exclusions. Should be workspace-wide, never per channel.
T
- TCPA
- The US Telephone Consumer Protection Act, governing calls and SMS. Carries statutory damages per violation, which is why cross-channel opt-out failures are expensive.
- Template approval
- Meta's review process for business-initiated WhatsApp messages. Unapproved templates are rejected at the API rather than filtered later.
- Throughput
- How fast a channel permits sending — messages per second on 10DLC, sends per day on a warmed mailbox. Determined by reputation and registration, not by your plan.
W
- Warmup
- Gradually increasing send volume on a new mailbox or domain to build reputation before real campaign traffic begins. Typically 21 days minimum.
Most of these are handled for you
Warmup, suppression, DNC checks, quiet hours and template approval all run automatically before every send.