Marketing automation software and service

Automate your contact gathering, segmenting, their data enriching, sending right content at right timingg. Mailbow empowers organizations to communicate with their customers using source data and to send responsive beautiful emails via marketing automation.

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Mailbow Email Marketing Glossary

A/B Testing

Compares the effectiveness of two or more emails, in order to discover which has better response rate and consequently better sales conversion rate.

Above the Fold

The upper, visible part (without scrolling) of an email message. The fold may be affected by the users’ monitor-size, resolution, and type of email programs (different in hotmail or gmail).

Acceptable Spam Report Rate

The rate at which you can be reported as SPAM without harming your “sender reputation”. Anything over 1 report per 1000 emails will get a warning.

Acceptance Rate

The percentage of emails that are accepted by the mail server. This is dependent on the reputation of the sender and other factors, if this number goes over 0.1% it may affect the deliverability of your messages.Just because your email is accepted by the mail server, it doesn’t necessarily mean that it will get to an inbox.

Acquisition Cost

The cost to have one new subscriber or customer in a specific email campaign. It is calculated by dividing the number of new subscribers or customers with the total campaign expenses. 

Ad Swap

Act of exchanging ads with other website owner via newsletters or websites at no charge. These are usually in a form of banners or photos and the value is determined by placement, size of list, quality of list, etc.

Affirmative Marketing

Type of performance based marketing where companies reward their affiliates for the visitors or new customers brought to them by their marketing efforts.

Affirmative Consents

A request by a subscriber to receive advertising or promotional information or newsletter through an opt-in form on the website. 

Application Program Interface (API)

Is a set of programming instructions for accessing a web based software application. In other words, how an application (program) is communicating with another software. A client may have an API connection to load database information to an email vendor automatically.


Process that verifies an email sender's identity. In email marketing, there are four main types of authentication: Domain Keys, DKIM, Sender ID, and SPF.


Automated email message, for example a welcome message to all new subscribers or when somebody unsubscribes or when you are away from your work. This can be more than a single message, it can be several event-triggered emails.


A desired email not from a personal contact, it can be described as an email that you want but not right now. It differs from spam, because the recipient has signed up to receive it. 


A list of emails or IP addresses that have been reported or originating with known spammers. Companies or individuals can use blacklists to filter out unwanted emails. 


A refusal by an ISP or mail server not to accept an email message for delivery. 

Bounce Rate

It represents the percentage of email addresses that failed to receive the message that you sent because the message was returned by the mailer server. 

Bulk Mail

Refers to emails that are filtered to the bulk folder of an email client. Also referred to as "Junk" or "Spam" folders in some email clients.


Popular name of the U.S. law regulating commercial email.

Click-Through Rate

Is the ratio of the the unique click-throughs on a link within an email to the total number of recipients of the email. 

Click-to-Open Rate

The ratio of unique click-throughs on a link within an email to the total number of unique opens of the email.


Is a privately held spam filter company that uses a network of users as a feedback mechanism to identify and block spam. 

CPM (Cost Per Thousand)

The cost to deliver your message to 1000 people. 

CTR (Click-Through Rate)

The percentage of people that click on a given URL in your email.

Conversion Rate

The percentage of those who respond to your call to action in your email campaign. It is used to measure the success of the campaign. 

Content Filters

Software filters with the aim to identify spam and filter them to junk or bulk folders by using words, phrases or header information within the email itself. 


Getting your emails delivered to the right place.


The number of emails that reached the inbox or junk folders. This is the number of total emails send out minus the bounced emails. 


Is a technical method for validating what domains emails are sent from. This protects the e-mail address against being used as part of identity theft. Technically, DKIM provides a method for validating the domain name identity that is associated with the email through cryptographic authentication.

Dedicated IP

It refers to an IP address from which only you send email.

Double Opt-In

The recommended method of building an email list, it requires subscribers to confirm their opt in by clicking a link in a confirmation email or responding to the confirmation email in some other way.


A company’s registered name on the internet, for example 

Domain Name System (DNS)

Is an internet service that translates domain names to IP addresses. The domain names are alphabetic and the internet is based on IP addresses and DNS service must translate the name into the corresponding IP address. For example the domain name might translate to

Domain Keys

Is an anti-spam software that uses public key cryptography to authenticate the sender’s domain, it is designed to verify the DNS domain of an email sender and the message integrity.

Dynamic content

Email-newsletter content that changes from one recipient to the next according to a set of variables, usually it can reflect past purchases, current interests or location if the recipient. 

Email Client

A program used to read and send email messages. 

Email Service Provider (ESP)

It can be defined as a company providing email services like email marketing or sends bulk email on behalf of their clients. 

Email Campaign

Series of emails designed to accomplish the marketing goal of the company. 

Email Filter

A technique used to block email based on different values, for example based on the sender, subject line, or content of an email.

Email Sponsorships

It’s when advertisers or companies pay to have their ad inserted into the email.

False positive

It happens when a wanted, good email is blocked as spam or incorrectly filtered. 

Feedback Loop

It is used by some ISP companies that processes the feedback of the email receivers, for example it automatically removes users from lists if they mark an email as spam. 


It’s a technique used to prevent spammers. A mail server using greylisting can temporarily reject any email from a sender it does not recognize. The receiver presumes the sender is legitimate, the originating server will try again to send it later and then the receiver will accept it. Greylisting presumes that if the sender is a spammer, they will not retry later to transmit their message. 

Hard Bounce

It happens when an email is sent to an invalid, closed or not existent email accoun. These are identified with 500 series SMTP reply code. 

House List (or Retention List)

It’s your email list that you built yourself with opt-in subscribers. 

HTML Email

Sending HTML email makes it possible to get creative with the design of your emails.


It is referred to the email recipients who haven’t taken any action on the email you sent out.

Inbox Placement Rate (IPR)

The ratio of emails that were delivered and the ones that ended up in the junk folder. 


Internet Message Access Protocol, a standard protocol for accessing email from a server. 

IP Address

A unique number assigned to each device connected to the Internet. If the IP address is dynamic, it changes each time an email message or campaign goes out, and if it is static it doesn’t change. Dynamic IP addresses can trigger spam filters.

IP Warmup

Sending a progressively increasing number of emails out of an IP address in order to build the IP's reputation.

Internet Service Provider (ISP)

A company that provides access to consumers and business to the internet.

Landing Page

It’s a page on your website that is linked from a specific email or address. It is used to provide additional information about the product or service mentioned in the email's call-to-action. Campaigns with a landing pages can give a quite accurate statistics about the visitors so its easier to measure its effectiveness. 

List Segmentation 

It means sending out emails based on a specific subscriber information. You can segment your customers by name, country or gender, in this way you can divide your customers into groups with similar interests and behaviours thus you get higher response rate and less unsubscribes. 

List Fatigue

A condition producing many unsubscribes or spam complains from a mailing list whose members are sent too many offers or too many emails in a short period of time.

List Hygiene

It means maintaining your lists so you remove the hard bounces and unsubscribe emails from your lists. 

List Purchase

It happens when an advertiser buys a list and uses as its own. This practice is not advised, since it can lead to high number of complaints and because of this the list be a poor quality one. 

List Rental

It happens when an advertised pays a list owner for usage of the list, but the advertisement is sent out in the name of the list owner. In this case the advertiser never gains full access to the list. This can be successful when the segmentation is very well done. 

Mail bomb

It’s an attack on a mail server by sending more messages than it can handle in a short period of time, the aim is being shutting it down.

Mailing list

A list of email addresses that can receive emails from a company or business. 

Mail loop

A communication error between two email servers, resulting from servers that generate automatic replies or responses. If an automated email triggers another automatic response on the other side an email loop is created. 

MTA (Mail Transfer Agent)

Is a software that transfers email messages for relay or delivery from one computer to another. MTAs are programs that are responsible for routing emails.

MUA (Mail User Agent)

Also referred as an email client or email reader is a program used to access and manage your emails. For example: Microsoft Outlook, IBM Lotus Notes, Thunderbird, KMail, Apple Mail, etc. 

Open Rate

The number of HTML message recipients who opened your email, usually as a percentage of the total number of emails sent. The open rate is considered a key metric for judging an email campaign's success, but it has several problems. The rate indicates only the number of emails opened from the total amount sent, not just those that were actually delivered. Opens also can't be calculated on text emails, as it is dependant on image downloads. Also, some email clients allow users to scan message content without actually opening the message, which is falsely calculated as an open.


It means to express permission by a customer to allow a marketer to send the messages. Opt-in marketing means sending emails only to users who requested these messages for example by subscribing to a list. 


It’s the opposite of opt-in, it expresses instruction by a recipient of an email to stop the marketer from sending more message. Responsible companies include opt-out option (unsubscribe) in their newsletters. 


Adding elements to your email that makes the message more personal, you can do this with the information you already know about them. For example the recipient name, location or referencing to past purchases. 

Physical Address

Address of the company usually it can be found in the footer of the email. Its inclusion is a legal requirement for all email marketing.

Plain Text Email 

An email sent without HTML. When sending an HTML message with pictures in it you should always give your recipients the option to read emails in plain text as well for better readability, because most of the email providers don’t display the images by default. 

Privacy Policy 

Is a legal document about a website or company’s policy that discloses the ways a website collects, uses or manages the customers data or information.


It’s a fraudulent activity of sending emails in name of other companies in order to get individuals sensitive personal information, such as credit card, social security numbers or other data.

POP (Post Office Protocol)

A communication protocol for retrieving emails from an email server. 


The person who manages mail servers at a company.

Read Rate

The percentage of emails that are set as “read” in their email client. This number is not as high as the open rate, but it is more accurate, because it is not dependent on the image download. 

Re-engagement Campaign

An email campaign with the aim to reactivate the non-responders in order to improve their opens, clicks and conversions. In the campaign only the “not active” list members are targeted. 


Is set by a variety of metrics like complaint rate, unknown user rate, volume, etc. and the final sender reputation consists both of domain and IP reputation. Reputation is important when a ISP determines whether an email should go to the inbox or junk folder. 

Responsive Design

Allows your email to automatically resize itself to optimize for whatever device or resolution is used to read your email.

Reverse DNS (rDNS)

Is a popular method for catching the spammers. In this process the IP address is matched to a domain name, instead of a domain name being matched to an IP address. It’s against those who use invalid IP addresses. 

Shared IP 

Ait is an IP address from which many people send emails.

Signature File

A block of text at the end of an email message that provides additional information such as company name, physical address, and contact information.

Single Opt-In

This kind of list is created when somebody signs up for email communications, but doesn’t confirm the action. 

Soft Bounce

Happens when an email fails to be delivered due to a temporary issue, like a full mailbox.

Spam or UCE (Unsolicited Commercial Email) 

Email sent to somebody who has not opted-in.

SPF - Sender Policy Framework

Stops spammers from forging the “from” part of an email. It provides the authentication by specifying which computers are authorized to send email from a specific domain. 


List of approved IP addresses that can send email to a recipient. 
Add new comment autor, 16.02.2019
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