Model Context Protocol (MCP)
The Model Context Protocol is an open standard that lets AI applications such as Claude and ChatGPT connect to outside tools and data through a common interface. G1
An MCP server exposes tools (for example: import contacts, render a preview, prepare a send) that the AI app can call during a conversation.
MCP connector
An MCP connector is a remote MCP server added to an AI app, so the assistant can use that service's tools inside a chat. G1
Claude calls these custom connectors; ChatGPT adds them as custom MCP servers under Plugins. Tellnod is added this way with one connector address.
Approval card (two-step send)
An approval card is an interactive card in the chat that shows exactly what will be sent and to whom, and holds the only button that can confirm the send.
In Tellnod the assistant prepares a send, which freezes the audience; the person confirms on the card. The confirmation is single-use and expires after 10 minutes.
Double opt-in
Double opt-in means a new subscriber confirms their address by clicking a link in a confirmation email before they receive marketing email.
It proves the address is real and that its owner agreed, which keeps complaint rates low and gives you a clear consent record.
Single opt-in
Single opt-in adds a subscriber as soon as they submit the form, without a confirmation email.
It grows a list faster than double opt-in but lets typos and fake addresses through.
Consent record
A consent record stores when, where and how a person agreed to receive marketing messages.
Privacy laws such as GDPR expect you to show this on request. Tellnod keeps it for every contact and does not mark imported contacts as subscribed without it.
SPF (Sender Policy Framework)
SPF is a DNS record that lists which servers may send email for your domain, so receiving inboxes can reject mail from anyone else. G3 G2
DKIM (DomainKeys Identified Mail)
DKIM adds a cryptographic signature to each email, checked against a public key in your DNS, proving the message came from your domain and was not altered. G4 G2
DMARC
DMARC is a DNS policy that tells inboxes what to do with email that fails SPF and DKIM alignment for your domain, and where to send reports. G5 G2
Gmail requires DMARC from senders of more than 5,000 messages a day to its users; a policy of p=none is accepted.
One-click unsubscribe
One-click unsubscribe lets a recipient leave a list with a single action in their inbox, using the List-Unsubscribe and List-Unsubscribe-Post headers defined in RFC 8058. G6 G2
Gmail requires it for marketing messages from bulk senders, alongside a visible unsubscribe link in the message body.
List-Unsubscribe header
List-Unsubscribe is an email header that gives inboxes a link or address for unsubscribing, so they can show their own unsubscribe button. G6
Spam complaint rate
The spam complaint rate is the share of delivered emails that recipients mark as spam. G2
Gmail recommends keeping the rate in Postmaster Tools below 0.10% and never reaching 0.30%. Tellnod pauses sending automatically above 0.1%.
Sender reputation
Sender reputation is how inbox providers rate a domain or IP address based on its history of authentication, complaints, bounces and engagement.
A good reputation is what gets campaigns into the inbox instead of spam.
Warm-up (ramp-up)
Warm-up means increasing sending volume gradually on a new domain or provider so inbox providers can build trust in it.
Tellnod ramps new accounts up automatically.
Hard bounce
A hard bounce is a permanent delivery failure, such as an address that does not exist; the address should not be emailed again.
Suppression list
A suppression list holds addresses that must never receive marketing email again, such as unsubscribes, hard bounces and spam complaints.
Preheader
The preheader is the short preview text an inbox shows next to or below the subject line.
If you do not set one, inboxes show the opening words of the email instead.
Segment
A segment is a group of contacts chosen by a rule, such as "ordered in the last 30 days" or "has not ordered in 60 days".
In Tellnod you describe the segment in plain words and check the count before sending.
Merge tag
A merge tag is a placeholder such as {{first_name}} that is replaced with each recipient's own data when the email is sent.
CAN-SPAM
CAN-SPAM is the US law for commercial email: it requires accurate headers, a non-deceptive subject, a valid postal address and a working way to opt out that you honor within 10 business days. G7
Marketing automation
Marketing automation is software doing repetitive marketing work for you, such as building segments, drafting messages, adding compliance footers or sending messages when a rule is met.
In Tellnod the assistant automates the work behind each campaign and you confirm every send; rule-based flows are planned for later.
Lifecycle email
A lifecycle email is sent at a stage of the customer relationship, such as a welcome after signing up, a thank-you after a first order or a win-back after a quiet period.
Click-through rate (CTR)
Click-through rate is the share of delivered emails in which a recipient clicked at least one link.
It is a more reliable signal than opens, because privacy features in some inboxes inflate open counts.
Conversion rate
For an email campaign, conversion rate is the share of recipients who completed the goal, usually an order, within a set attribution window.
Revenue per recipient
Revenue per recipient is the attributed revenue of a campaign divided by the number of people it was delivered to, which lets you compare campaigns of different sizes.
Attribution window
The attribution window is how long after a click an order still counts toward the email; Tellnod uses 7 days.
Sources
- [G1] Model Context Protocol: introduction, checked
- [G2] Google Workspace Admin Help: Email sender guidelines, checked
- [G3] RFC 7208: Sender Policy Framework (SPF), checked
- [G4] RFC 6376: DomainKeys Identified Mail (DKIM) Signatures, checked
- [G5] RFC 7489: Domain-based Message Authentication, Reporting, and Conformance (DMARC), checked
- [G6] RFC 8058: Signaling one-click functionality for list email headers, checked
- [G7] FTC: CAN-SPAM Act compliance guide for business, checked