Basic configuration

SPF

The Sender Policy Framework is a means of sender verification designed to make sender address forgery or impersonation more difficult. This allows the receiving server to verify if the system sending on behalf of a domain is in fact authorized to send messages with the sender domain in question. To authorize the Retarus relays to send messages on your behalf, add the following SPF record to your DNS:

CODE

v=spf1 include:_spf.general.transactional-mail-a.com ~all

For the 'MAIL FROM' address specified in the SMTP communication between email servers, an SPF-From Record must be entered, thereby allowing an SPF test to be carried out on the recipient side. The SPF Record must end in "-all" or "∼all". In case the necessary entries are not made on the Customer's side within ten (10) business days, the re-verification efforts and expenses will be charged in accordance with Retarus’ agreed hourly rates.

DKIM

The use of the DKIM (DomainKeys Identified Mail) method is mandatory. For each sender domain registered with Retarus on behalf of the Customer, the Customer must store a corresponding DKIM key in their DNS (generated and provided by Retarus). If the Customer fails to make the necessary entries within ten (10) business days, the reverification will be billed in accordance with Retarus’ agreed hourly rates.

DMARC

DMARC lets Customer tell receiving servers what to do with messages from the Customer's domain that don’t pass SPF or DKIM. The authenticating domain must be the same domain that's in the message From: header. It is the responsibility of the Customer to publish a DMARC record within the DNS zone for each sender domain. If there is no DMARC record, create one with a “none” tag policy as below:

CODE

v=DMARC1; p=none; rua=mailto:rua@example.com; ruf=mailto:ruf@example.com; fo=1