Cold email

Last updated November 30, 2024

A cold email is an unsolicited e-mail that is sent to a receiver without prior contact. It could also be defined as the email equivalent of cold calling. Cold emailing is a subset of email marketing and differs from transactional and warm emailing.

Cold email is a personalized, one-to-one message targeted at a specific individual. Its aim is to get into a business conversation with that individual, rather than to promote a product or a service to the masses. Cold email, according to its proponents, is not spam. Cold emailing is distinct from spam in that it aims to initiate a genuine conversation rather than deceive the recipient. However, if certain steps are not followed, it may be treated as spam by spam filters or reported by the recipients.

Email deliverability

Email deliverability is the percentage of emails that got successfully delivered to the primary inbox, instead of getting blocked or classified as spam.

Email deliverability is not the same as email delivery. Email delivery is the percentage of emails that got successfully delivered to the recipient's email address, regardless of whether it is the main inbox or any other folder, including spam.

Email deliverability is especially important for cold email senders because their goal is to have their email delivered to the recipients' main inbox.

Factors decreasing email deliverability

Low email deliverability may result from:

Bad domain reputation

Domain reputation of the sender is a key factor.^[1] The specific domain name may lose its reputation if the emails are being sent in large quantities at once and with too high a frequency. The recipient's email server may consider such behavior as spamming and blocklist the domain used for sending emails.

A domain may also be blocklisted if spam filters detect spam words in the subject line, within the email content, or when other spamming techniques are used.

A domain's age is an important factor in determining a domain's reputation. A new domain has a neutral reputation by default. However, its activity is closely monitored by spam filters. If the email providers detect suspicious use of a domain, for example, sending a big number of emails in a short period of time, any such activity will be flagged and the domain may lose its reputation. To use a domain for cold email outreach, it is recommended to warm it up first.

Bad server IP reputation

Each email sender is assigned an IP address, and this IP address' reputation can be assessed. If an IP address is associated with spam activities, its reputation gets harmed.

An IP address may be shared or dedicated. The reputation of a shared IP address depends on all the users who are assigned to it. If one of the users sends emails marked as spam by spam filters or email recipients, the shared IP address's reputation is harmed. The reputation of a dedicated IP address depends solely on the specific user to whom it is assigned.

A new IP address has a neutral reputation and needs to be warmed up first in order to build up a good reputation.

Emails sent by the IP address that has a bad reputation would be classified as spam. Ultimately, the IP address associated with spam activity may be blocked by the Internet Service Provider.^[2]^[3]

How to warm-up servers IPs

It is easier to establish a good reputation as a new sender if you warm up your domains.^[4]^[5]

IP warm-up age is the main factor to make a good reputation for your server. You can set a limit on your server to:

1 day limit - 20 email/day
2 day limit - 30 email/day
3 day limit - 45 email/day
45 email/day after the initial 3 days.

Bad email address reputation

An email address can be appointed with a bad or good reputation based on its sending history. If the emails are treated as spam by spam filters or reported by the recipients, the email address loses its reputation and further emails are placed into the spam folder or are entirely blocked by the Internet Service Provider.

Email address, similarly to a domain or IP address, requires a warm-up process before it can be used for sending cold email campaigns.

No SPF and DKIM records set up on a domain's DNS server

Both SPF and DKIM records protect the domain from email spoofing and phishing attacks.

SPF record authenticates the email message sent from an authorized domain's DNS server on which the SPF is set up.

DKIM record affixes a digital signature linked to a domain name to each outgoing email. It ensures that the message was sent from an authorized domain's DNS server.

Setting up both DKIM and SPF on a domain's DNS server positively influences domain reputation.^[6]^[7]

Exceeding the email provider’s sending limits

Each email provider has its own email sending limits that can be found on their websites. The limits may be daily, hourly, or sometimes even per minute. Exceeding the limits may result in blocking the email account for a time period determined by an email host.

Problems with email content

Spam words: After the recipient's server receives the email and checks several factors, such as domain and IP reputation, the email content and subject line are evaluated by spam filters.^[8] There are specific words, usually overused by the spammers, that alarm spam filters, and the message is treated as spam. The anti-spam software is continuously analyzing and modifying the spam word list based on user's feedback and behavior, such as marking specific emails as spam or retrieving them from a spam folder.
Misleading subject line: Subject lines that aren't relevant to the email body may cause the recipients to feel misled. They may mark such messages as spam, thus damaging the domain and email address reputation.
Lack of personalization: The recipients may report the emails as spam if they do not consider the message relevant or valuable to them. Personalization adds uniqueness to each message. Identical and generic emails are not only suspicious to humans, but also to spam filters.
Extensive use of HTML, GIFs, pictures, or videos: Emails, which include images, GIFs, or videos may be treated as suspicious by the spam filters. Replacing text with a picture in the content of an email has been a common practice of spammers who want to con spam filters and avoid spam word detection by optical character recognition. Too complex or broken HTML code in the email body may cause the message to display incorrectly, thus the message may be considered a phishing attempt or spam and may get reported as such by the recipient.
Attachments: Emails with attachments sent from an unknown sender raise the recipients’ suspicion because such files are often identified with malware and computer viruses.
Links and tracking: Too many links in a message may be considered suspicious by both spam filters and the recipients. Spammers tend to avoid using spam words in the email body by including links instead. If a sender includes a link to a non-trustworthy source, it can trigger SPAM filters. Many people use pixel-tracking technology to find out if their emails had been opened. The way this technology works, a transparent image that is the size of one pixel is placed somewhere in the email body. When someone opens the email they send a request to the server where the image is located in order to download that image. This download request is how the sender knows that their email was opened. Even though this technology is used by the majority of businesses that send a large number of emails, it has its downside. SPAM filters are created to protect the user from any unwanted content. Because of this, some people use filters that block emails containing transparent or the same color as background images. This is why sometimes email tracking can trigger SPAM filters.

Sending volume and frequency

Sending volume is connected with the email provider's sending limit. The email provider determines the number of emails that can be sent per minute or hour. If too many emails are sent in a given period of time the email provider may block the sending process.

Also, if the number of emails sent increases significantly over a certain amount of time, it may be a sign for spam filters that the emails are not sent manually. Any non-human behavior alarms the spam filters, which results in the emails being placed in a spam folder.

High hard bounce rate

Sending emails to a big number of invalid or non-existent email addresses results in a high hard bounce rate, which in turn alarms the mailbox providers who may block the sender.

High soft bounce rate

Soft bounces take place when an email is turned back before reaching the recipient's server, hence, it is not delivered to their mailbox. The reason for a soft bounce can be typically one of these:

A full inbox of the recipient
Out-of-office status
Email server is down or offline
Email body is too large^[9]

Good Open rate for Cold Email

If a cold outreach campaign has a 50% open rate, it is considered successful. The stats can't be tampered with, and anything below 50% suggests the campaigns need to be modified.^[10]

Rules and regulations

Below are the summaries of some example data protection legislation and laws restricting the use of unsolicited emails. A complete list of internal rules and regulations around the world can be found here.

The General Data Protection Regulation aims primarily to give the European Union citizens control over their personal data and to simplify the regulatory environment for international business.^[11]

All the individuals who send cold emails to the citizens of the EU are required to comply with the GDPR because they collect and process personal data, in this context, an email address connected to an identifiable individual at minimum.

In order to respect the GDPR while sending cold emails, an individual should abide by the specific principles:

all the actions taken to build an email list should be legal, fair, and transparent;
all the personal data collected must be adequate and relevant to the purpose of its processing;
it is the data processor's responsibility to ensure that the data processed is accurate and up-to-date at all times;
the personal data should only be stored for the time necessary for the purpose of its processing. Individuals whose data is processed should be enabled to exercise their right to be forgotten and a right to assist in data deletion;
data administrator is responsible for the security of the personal data being processed. The data must not be shared with any third party without a clear consent of data owners.

CCPA

The California Consumer Privacy Act regulates the ways personal information of California Citizens is used by businesses that get their revenue from selling consumer's personal data. CCPA focuses on data collection and privacy and gives California Citizens:^[12]

a right to be informed about what kind of information is collected about them and how it is processed;
a right to request information erasure unless the information is necessary to provide a service;
a right to object to the sale of their personal information.

CAN-SPAM Act

Source:^[13]

The CAN-SPAM Act set first national standards for sending commercial emails in the USA. According to the CAN-SPAM Act:^[14]

every email recipient should have a right to opt-out from getting unwanted emails. Cold email senders should respect the recipient's request to be deleted from their contacts;
the “from” line should be accurate;
the subject line should be relevant to the content of an email;
the sender's physical address should be clearly visible in the content of an email or a signature.

Canada's Anti-Spam Legislation (CASL)

The CASL gives the citizens of Canada the right to:^[15]

request not to get further emails from a particular sender;
know the identity and physical address of a sender;
refuse or withdraw the consent to get the emails from a particular sender;
know the nature and purpose of an email.

Australian Spam Act

The Spam Act regulates in what cases commercial emails, including cold emails, can be sent and what must be included in the content. It states that commercial emails:^[16]

cannot be sent without the recipient's clear or inferred consent;
must contain a name and contact details of a sender;
must contain a clear way to opt-out from receiving them;
must be relevant to the recipient.

New Zealand – Unsolicited Electronic Messages Act

The Unsolicited Electronic Messages Act regulates sending unsolicited commercial emails, including cold emails, with a New Zealand link, that is, emails that are sent to, from, or within New Zealand. According to the Act:^[17]

the commercial emails cannot be sent without the recipient's clear or inferred consent;
the commercial email must contain accurate information about the sender of the message, including valid contact information;
the recipient must have a clear way to opt-out from receiving such emails.

Local personal data protection regulations and laws restricting the use of unsolicited emails may be subject to change. Cold email senders must keep up to date with the amendments to such regulations in order to always act in compliance with the law.

Cold email trends and best practices change with time. Many factors depend on the type of business and target recipients of the emails.

Related Research Articles

Email is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.

<span class="mw-page-title-main">Open mail relay</span> SMTP server that allows anyone to send e-mail through it

An open mail relay is a Simple Mail Transfer Protocol (SMTP) server configured in such a way that it allows anyone on the Internet to send e-mail through it, not just mail destined to or originating from known users. This used to be the default configuration in many mail servers; indeed, it was the way the Internet was initially set up, but open mail relays have become unpopular because of their exploitation by spammers and worms. Many relays were closed, or were placed on blacklists by other servers.

A whitelist or allowlist is a list or register of entities that are being provided a particular privilege, service, mobility, access or recognition. Entities on the list will be accepted, approved and/or recognized. Whitelisting is the reverse of blacklisting, the practice of identifying entities that are denied, unrecognised, or ostracised.

Various anti-spam techniques are used to prevent email spam.

Mobile phone spam is a form of spam, directed at the text messaging or other communications services of mobile phones or smartphones. As the popularity of mobile phones surged in the early 2000s, frequent users of text messaging began to see an increase in the number of unsolicited commercial advertisements being sent to their telephones through text messaging. This can be particularly annoying for the recipient because, unlike in email, some recipients may be charged a fee for every message received, including spam. Mobile phone spam is generally less pervasive than email spam, where in 2010 around 90% of email is spam. The amount of mobile spam varies widely from region to region. In North America, mobile spam steadily increased after 2008 and accounted for half of all mobile phone traffic by 2019. In parts of Asia up to 30% of messages were spam in 2012.

<span class="mw-page-title-main">Email spam</span> Unsolicited electronic advertising by email

Email spam, also referred to as junk email, spam mail, or simply spam, is unsolicited messages sent in bulk by email (spamming). The name comes from a Monty Python sketch in which the name of the canned pork product Spam is ubiquitous, unavoidable, and repetitive. Email spam has steadily grown since the early 1990s, and by 2014 was estimated to account for around 90% of total email traffic.

Sender Policy Framework (SPF) is an email authentication method which ensures the sending mail server is authorized to originate mail from the email sender's domain. This authentication only applies to the email sender listed in the "envelope from" field during the initial SMTP connection. If the email is bounced, a message is sent to this address, and for downstream transmission it typically appears in the "Return-Path" header. To authenticate the email address which is actually visible to recipients on the "From:" line, other technologies such as DMARC must be used. Forgery of this address is known as email spoofing, and is often used in phishing and email spam.

A Joe job is a spamming technique that sends out unsolicited e-mails using spoofed sender data. Early Joe jobs aimed at tarnishing the reputation of the apparent sender or inducing the recipients to take action against them, but they are now typically used by commercial spammers to conceal the true origin of their messages and to trick recipients into opening emails apparently coming from a trusted source.

A bounce message or just "bounce" is an automated message from an email system, informing the sender of a previous message that the message has not been delivered. The original message is said to have "bounced".

Email authentication, or validation, is a collection of techniques aimed at providing verifiable information about the origin of email messages by validating the domain ownership of any message transfer agents (MTA) who participated in transferring and possibly modifying a message.

<span class="mw-page-title-main">Message submission agent</span>

A message submission agent (MSA), or mail submission agent, is a computer program or software agent that receives electronic mail messages from a mail user agent (MUA) and cooperates with a mail transfer agent (MTA) for delivery of the mail. It uses ESMTP, a variant of the Simple Mail Transfer Protocol (SMTP), as specified in RFC 6409.

Email spoofing is the creation of email messages with a forged sender address. The term applies to email purporting to be from an address which is not actually the sender's; mail sent in reply to that address may bounce or be delivered to an unrelated party whose identity has been faked. Disposable email address or "masked" email is a different topic, providing a masked email address that is not the user's normal address, which is not disclosed, but forwards mail sent to it to the user's real address.

A challenge–response system is a type of that automatically sends a reply with a challenge to the (alleged) sender of an incoming e-mail. It was originally designed in 1997 by Stan Weatherby, and was called Email Verification. In this reply, the purported sender is asked to perform some action to assure delivery of the original message, which would otherwise not be delivered. The action to perform typically takes relatively little effort to do once, but great effort to perform in large numbers. This effectively filters out spammers. Challenge–response systems only need to send challenges to unknown senders. Senders that have previously performed the challenging action, or who have previously been sent e-mail(s) to, would be automatically receive a challenge.

DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email, a technique often used in phishing and email spam.

Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email authentication protocol. It is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. The purpose and primary outcome of implementing DMARC is to protect a domain from being used in business email compromise attacks, phishing email, email scams and other cyber threat activities.

Email forwarding generically refers to the operation of re-sending a previously delivered email to an email address to one or more different email addresses.

MailChannels is a Canadian technology company that specializes in email security for businesses and internet service providers (ISPs). Founded in 2004 by Ken Simpson and headquartered in Vancouver, British Columbia, the company operates in email security and the infrastructure market. The business provides a products and services designed to safeguard email systems against spam, phishing, and other harmful content. They guarantee the dependable delivery of legitimate messages and offer a mail relay API for numerous websites.

Backscatter is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.

A feedback loop (FBL), sometimes called a complaint feedback loop, is an inter-organizational form of feedback by which a mailbox provider (MP) forwards the complaints originating from their users to the sender's organizations. MPs can receive users' complaints by placing report spam buttons on their webmail pages, or in their email client, or via help desks. The message sender's organization, often an email service provider, has to come to an agreement with each MP from which they want to collect users' complaints.

Spam reporting, more properly called abuse reporting, is the action of designating electronic messages as abusive for reporting to an authority so that they can be dealt with. Reported messages can be email messages, blog comments, or any kind of spam.

References

↑ "How to improve domain reputation for better email deliverability". postmarkapp.com. Retrieved 2023-04-02.
↑ "IP reputation". www.ibm.com. 2015-02-27. Retrieved 2024-11-29.
↑ Esquivel, Holly and Akella, Aditya. "On the Effectiveness of IP Reputation for Spam Filtering".University of Wisconsin-Madison. Retrieved 2024-11-29.
↑ "Warming up an IP Address". twilio.com. Retrieved 2024-06-28.
↑ "IP Warm-up Strategy Overview". sparkpost.com. 2020-10-01. Retrieved 2024-06-28.
↑ "SPF record: Protect your domain reputation and email delivery". postmarkapp.com. 2024-02-20. Retrieved 2024-06-28.
↑ "DKIM: What is it and why is it important when sending emails?". postmarkapp.com. 2024-03-04. Retrieved 2024-06-28.
↑ Karim, Asif; Azam, Sami; Shanmugam, Bharanidharan; Kannoorpatti, Krishnan; Alazab, Mamoun (2019). "A Comprehensive Survey for Intelligent Spam Email Detection". IEEE Access. 7: 168261–168295. doi:10.1109/ACCESS.2019.2954791. ISSN 2169-3536.
↑ Salvi, Anil (2023-06-12). "Email Bounce: How To Fix Email Bounce Back Effectively?". SalesHandy. Retrieved 2024-09-03.
↑ A Complete Guide to Mastering Cold Email Outreach
↑ "Regulation (EU) 2016/ 679 of the European Parliament and of the Council". Official Journal of the European Union. 27 April 2016.
↑ "Bill Text - AB-375 Privacy: personal information: businesses". leginfo.legislature.ca.gov. Retrieved 2019-01-02.
↑ "CAN-SPAM Act: A Compliance Guide for Business". Federal Trade Commission. 2009-09-02. Retrieved 2023-04-02.
↑ "LegalArchiver.Org: Can-Spam Act 2003". 2016-02-13. Archived from the original on 2016-02-13. Retrieved 2019-01-02.
↑ Government of Canada, Industry Canada (2014-06-30). "Canada's Anti-Spam Legislation - Canada's Law on Spam and Other Electronic Threats - Home". fightspam.gc.ca. Retrieved 2019-01-02.
↑ Authority, The Australian Communications and Media (2018-12-10). "Spam Industry obligations". www.acma.gov.au. Retrieved 2019-01-02.
↑ "Unsolicited Electronic Messages Act 2007 No 7 (as at 13 November 2018), Public Act Contents – New Zealand Legislation". www.legislation.govt.nz. Retrieved 2019-01-02.

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[1] "How to improve domain reputation for better email deliverability". postmarkapp.com. Retrieved 2023-04-02.

[2] "IP reputation". www.ibm.com. 2015-02-27. Retrieved 2024-11-29.

[3] Esquivel, Holly and Akella, Aditya. "On the Effectiveness of IP Reputation for Spam Filtering".University of Wisconsin-Madison. Retrieved 2024-11-29.

[4] "Warming up an IP Address". twilio.com. Retrieved 2024-06-28.

[5] "IP Warm-up Strategy Overview". sparkpost.com. 2020-10-01. Retrieved 2024-06-28.

[6] "SPF record: Protect your domain reputation and email delivery". postmarkapp.com. 2024-02-20. Retrieved 2024-06-28.

[7] "DKIM: What is it and why is it important when sending emails?". postmarkapp.com. 2024-03-04. Retrieved 2024-06-28.

[8] Karim, Asif; Azam, Sami; Shanmugam, Bharanidharan; Kannoorpatti, Krishnan; Alazab, Mamoun (2019). "A Comprehensive Survey for Intelligent Spam Email Detection". IEEE Access. 7: 168261–168295. doi:10.1109/ACCESS.2019.2954791. ISSN 2169-3536.

[9] Salvi, Anil (2023-06-12). "Email Bounce: How To Fix Email Bounce Back Effectively?". SalesHandy. Retrieved 2024-09-03.

[10] A Complete Guide to Mastering Cold Email Outreach

[11] "Regulation (EU) 2016/ 679 of the European Parliament and of the Council". Official Journal of the European Union. 27 April 2016.

[12] "Bill Text - AB-375 Privacy: personal information: businesses". leginfo.legislature.ca.gov. Retrieved 2019-01-02.

[13] "CAN-SPAM Act: A Compliance Guide for Business". Federal Trade Commission. 2009-09-02. Retrieved 2023-04-02.

[14] "LegalArchiver.Org: Can-Spam Act 2003". 2016-02-13. Archived from the original on 2016-02-13. Retrieved 2019-01-02.

[15] Government of Canada, Industry Canada (2014-06-30). "Canada's Anti-Spam Legislation - Canada's Law on Spam and Other Electronic Threats - Home". fightspam.gc.ca. Retrieved 2019-01-02.

[16] Authority, The Australian Communications and Media (2018-12-10). "Spam Industry obligations". www.acma.gov.au. Retrieved 2019-01-02.

[17] "Unsolicited Electronic Messages Act 2007 No 7 (as at 13 November 2018), Public Act Contents – New Zealand Legislation". www.legislation.govt.nz. Retrieved 2019-01-02.

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