SPF record for emails

[kolb]

how to hide the 'mailed by' address for SPF from the secondary domain which shows the primary domain name.
I am an admin of a workspace. I have added a secondary domain and then set up an email alias for the secondary domain. Then in the Gmail settings under account -> send mail as-> I have added the email alias of the secondary domain. Now when I send mail from that secondary domain email address, it displays the following thing to the recipient:

Mailed by: primary domain name
Signed by: secondary domain name

I want to either show (when mailed from a secondary domain email address) :

Mailed by: secondary domain name or hide it (and only show signed by: secondary domain name)

[ajojose33333344]

@kolb I think its an expected scenario when you are using another domain email address to send emails through.

you will have to create a separate google workspace account for your secondary domain address if you don't want users to see this.

But to be honest usually no one reads this signed by and mailed by

[cryptochrome]

Yes, it is expected behavior. Because you are using an alias, you are mailing from your primary domain, but a different from: address. This is visible in the email headers and the receiving end will show this. 

As @ajojose33333344 mentioned, if you set up an actual account in the secondary domain and send from there, it will be authenticated/signed from the secondary domain.