A

A/B split:
Above the fold
Access
Acquisition cost
Ad swap
Affiliate
Affirmative consent
Alert
AOL
Application Program Interface (API)
Application Service Provider (ASP)
Attachment
Authentication
Autoresponder

B

B-to-B
B-to-C
Bayesian filter
Blacklist
Block
Bonded Sender
Bounce
Bounce handling
Bounce message
Bounce rate (also return rate)
Broadcast
Bulk folder (also junk folder)

C

Call to action
CAN SPAM
Catch-all
Cell
CGI
Challenge-response system
Churn
Clickthrough & Clickthrough tracking
Clickthrough rate
Co-registration
Commercial email
Confirmation
Confirmed opt-in
Content
Conversion
CPA
CPC
CPM
Creative
CRM
Cross-campaign profiling
Cross-post
CTR

D

Dedicated Server
Deduplication (deduping)
Delivered email
Delivery tracking
Denial-of-service attack (DOS)
Deploy
Digest
Discussion group
Domain Name System
DomainKeys
Double opt-in
Dynamic content

E

ECOA
Effective rate
Email address
Email appending
Email client
Email Domain
Email filter
Email Friendly Name
Email harvesting
Email newsletter
Email Prefix
Email vendor
Enhanced whitelist
Event triggered email
Ezine (also e-zine)

F

False positive
FAQ
Filter
Firewall
Footer
Forward (also Forward to a Friend)
From
Full-service provider

G

Gmail
Goodbye message

H

Hard bounce
House list
HTML message
Hygiene

I

IMAP
Impression
IP address
ISP

J

Joe job

L

Landing page
Linkrot
List
List fatigue
List host
List hygiene
List management
List owner
List rental
List sale

M

Mail bomb
Mail loop
Mailing list
mailto:
MSP
MTA
MUA
Multi-part MIME
MX

N

Nth name

O

Open rate
Open relay
Opt-in
Opt-out

P

Pass-along
Permission
Personalization
PGP (Pretty Good Privacy)
Phishing
Plain text
POP
Postmaster
Preferences
Preview pane
Privacy policy

Q

Queue

R

Read email
Registration
Relationship email
Reply-to
Reverse DNS
Rich Media

S

Seed emails
Segment
Select
Selective Unsubscribe
Sender ID
Sender Policy Framework (also SPF)
Sent emails
Server
Shared server
Signature
SMTP
Snail mail
Soft bounce
Solo mailing
Spamcop
Sponsorship swap
Spoofing
Subject line
Subscribe
Subscriber
Suppression file

T

Test
Text newsletter
Thank-you page
Throttling
Transactional email

U

UCE
Unique Reference Number
Unsubscribe
URL

V

Vendor
Verification
Video e-mail
Virus

W

Web bug (also Web beacon):
Welcome message
Whitelist
Worm