What is a custom DKIM signature and what are the benefits and best practices for using it?

Email marketer from SparkPost shares that DKIM is important for improving email deliverability. When you DKIM sign your emails, you are telling mailbox providers that you are a legitimate sender and that your emails should be delivered to the inbox, not the spam folder. This builds trust between the sender and the receiver.

Marketer from Email Geeks explains that different types of messages within your mail streams (e.g. corporate, marketing email, service desk) should have their own different custom DKIM signatures. If the autoresponder emails are not marketing related, then they should have a different signature. The objective is to help receivers understand the different types of email you are sending out.

Email marketer from Mailjet shares that DKIM is an email authentication method designed to detect email spoofing. It allows the receiving mail server to verify that an email claimed to have originated from a specific domain was indeed authorized by the owner of that domain. By using a digital signature, DKIM ensures that the message was not altered during transit.

Marketer from Email Geeks shares that it helps receivers differentiate your email stream from others, which can help with deliverability.

Marketer from Email Geeks explains that a custom DKIM signature means that the domain is using DKIM signing.

Email marketer from GlockApps explains that monitoring DKIM is essential for detecting and resolving any authentication issues. Regular monitoring helps to ensure that emails are properly authenticated and that the sender's reputation is protected. Tools like GlockApps provide DKIM monitoring and reporting capabilities.

Email marketer from SendGrid recommends using a DKIM key size of 2048 bits for optimal security. Shorter key lengths may be vulnerable to attacks, while longer key lengths provide better protection against spoofing and tampering. Regularly rotating your DKIM keys is also a good security practice.

Marketer from Email Geeks responds that if you have a very large email marketing programme with multiple distinct brands and domains then multiple (per-domain) DKIM signatures may be useful, otherwise, if you are just using your ESP to send from one domain then one custom DKIM signature is fine.

Email marketer from StackExchange user u/email_admin explains that to set up DKIM, you need to generate a public/private key pair, add the public key to your DNS record, and configure your email server to sign outgoing messages with the private key. Test your DKIM setup using online DKIM checkers to ensure that it is working correctly.

Email marketer from AuthSMTP explains that best practices for DKIM include using a key length of at least 2048 bits for stronger security, regularly rotating DKIM keys to minimize the impact of potential key compromise, and monitoring DKIM reports to identify and address any authentication issues.

Email marketer from EasyDMARC shares that implementing DKIM offers several benefits, including improved email deliverability, enhanced sender reputation, and protection against phishing attacks. DKIM ensures that your emails are authenticated, making it harder for attackers to spoof your domain and send malicious emails.

Email marketer from MXToolbox shares that validating DKIM involves verifying the DKIM signature in the email header against the public key published in the DNS record. Tools like MXToolbox can be used to check if a DKIM signature is valid and if the email has been tampered with during transit.

Marketer from Email Geeks explains that DKIM is an email authentication mechanism that allows a sender to apply a digital signature to an email and associate that signature with a domain name. It uses asymmetric cryptography where the public key is stored in the DNS and the private key is kept with the sender. Ideally you want to DKIM sign all of your outbound emails.

Email marketer from Reddit user u/email_expert shares that DKIM is a crucial component of DMARC (Domain-based Message Authentication, Reporting & Conformance). Implementing both DKIM and DMARC provides a strong defense against email spoofing and phishing attacks, ensuring that only legitimate emails are delivered to your recipients.

Email marketer from Postmark shares that DKIM helps to improve brand reputation by ensuring that your emails are properly authenticated and that your domain is protected from spoofing. A strong brand reputation leads to better email deliverability and improved customer engagement.

Expert from Spamresource answers that the purpose of DKIM is to provide a way for receiving email servers to verify that an email message was indeed sent from the domain it claims to be from and that the message has not been altered in transit. This is done by adding a digital signature to the email header, which the recipient's server can then validate against the sender's public key published in the DNS record.

Expert from Word to the Wise explains that DomainKeys Identified Mail (DKIM) provides a method for validating the source and integrity of email messages. It uses cryptographic signatures to verify that an email has not been altered during transit and that it originated from the claimed domain. Implementing DKIM helps to prevent email spoofing and phishing attacks, improving deliverability and building trust with recipients.

Documentation from Microsoft explains that DKIM works by adding a digital signature to the header of an email message. This signature is encrypted with the sender's private key and can be verified by the recipient's mail server using the sender's public key, which is published in the DNS record. If the signature matches, the email is authenticated.

Documentation from Google explains that DKIM signing lets you attach a digital signature to your outgoing messages. Receiving servers can then use DKIM to verify that messages weren't altered during transit and truly came from your domain. When you use DKIM, your domain takes responsibility for your messages. This increases trust and helps prevent spoofing.

Documentation from RFC Editor defines DKIM as a mechanism by which email senders can digitally sign their messages, in a way that can be verified by email receivers. This allows receivers to confirm that a message truly came from the claimed sender and was not altered in transit. DKIM provides an authentication framework for email.

Documentation from DKIM.org explains that DKIM works by generating a cryptographic signature for each email message and then attaching the signature to the message header. This signature can then be validated by the receiving mail server using the sender's public key, which is published in the domain's DNS records.