Configuring SPF entry for own E-mail sender

Created by Calenso Support, Modified on Wed, 28 Feb 2024 at 03:42 PM by Calenso Support


To enable the Calenso E-mail server to send e-mail messages (appointment confirmations and reminders) to customers on behalf of a Whitelabel domain, an SPF entry for Calenso must be made in the DNS settings of the Whitelabel domain.

DKIM TXT Entry for Calenso (Brevo)

1. configure the TXT entry (DKIM) for "mail._domainkey":


2. configure the TXT entry without a naming:



For Google- and Yahoo-hosted Mail-Server a TXT-Entry (DMARC) is additionally required. Name the entry "_dmarc":

v=DMARC1; p=none;


The entry must be created in the DNS settings of the Whitelabel domain. The DNS settings are the settings for the domain e.g.

Example of an entry in the DNS server settings:

Is the DKIM entry mandatory?

Calenso's e-mail sending will work even without the DKIM entry. However, Calenso cannot guarantee that the email messages will reach the recipients. As without the DKIM entry (Domain Key identified Mail), they are often marked as spam messages.

What is a DKIM entry?

When an email is sent, the recipient's server checks to determine if the message is legitimate and the sender authorized. These checks are possible by implementing the DKIM protocol on the sender's domain.

The DKIM (DomainKeys Identified Mail) protocol is a cryptographic protocol based on the use of public keys published in your DNS. The protocol allows you to sign your email with your domain name, like signing a letter with your signature. The recipient of your email can then be sure that the email they received was written by you and not altered during transmission. This protocol is particularly effective against man-in-the-middle attacks.

Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select atleast one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article