* Please note that custom domain DMARC/DKIM is only applicable to users who are utilizing ImprovMX SMTP. ImprovMX SMTP is a feature available to premium and business-tier users.
Domain-based Message Authentication, Reporting and Conformance (DMARC)
DMARC records allow domain owners to specify instructions for domain authorization using DKIM and/or SPF records. These instructions tell receivers how to handle mail if DKIM/SPF fail for the sender. This can drastically reduce the chances of email spoofing by only allowing specific senders to send from your domain.
There are many ways to deploy DMARC, but it's advisable that you start with a more relaxed policy before moving to a stricter one. If you're new to DMARC, we advise starting with the below record:
The above record tells senders that you've enacted DMARC (
v is the version) and assigns a policy (
p) of none, which instructs receivers to take no action if DKIM or SPF fail, while still requesting reports. With this policy, a domain owner can supply an additional
rua tag to receive aggregate reports at a particular URI or email. This allows the domain owner to review reports before moving to a stricter
reject policy. As an example,
v=DMARC1; p=none; rua=mailto:firstname.lastname@example.org; would allow a domain owner to receive aggregate reports at
For a more detailed explanation on DMARC, its importance, and deployment variations, please visit https://dmarc.org/
**It's important to note that some DNS providers and/or domain registrars automatically append your domain name to DMARC records. If this is the case, simply assign a hostname value of
_dmarc to your record.
DomainKeys Identified Mail (DKIM)
DKIM records affix a digital signature to an email which ensures that it has originated from an authorized sender of the domain. These signatures are attached to each piece of outgoing mail. When using ImprovMX SMTP, this record is required in tandem with a DMARC policy.
The below records allow for DKIM signing via ImprovMX SMTP on the premium and business subscriptions.
These CNAME records allow ImprovMX to properly attach a DKIM signature to your outgoing emails. These signatures indicate that mail is originating from ImprovMX as an approved sender of your domain.
To read more about DKIM signatures and their importance, please visit http://dkim.org/
**It's important to note that some DNS providers and/or domain registrars automatically append your domain name to DKIM records. If this is the case, simply assign a hostname value of
dkimprovmx2._domainkey to your record.
Have any further questions?