DKIM fail when also using SendinBlue/Brevo DKIM values

Help with Unusual Circumstances
1

I am getting DKIM fail because I am also using sendinblue DKIM records.

Entries for DKIM mailinbox are:

mail . _domainkey

v=DKIM1; h=sha256; k=rsa; s=email; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQE*******

Entries for sendinblue are:
mail. _domainkey
k=rsa;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNA***********

My errors in gmail is like this (
ARC-Authentication-Results: i=1; mx. google .com;
dkim=fail header.i=@******ech .com header.s=mail header.b=“cl/tUbWI”;…

Authentication-Results: mx. google.com;
dkim=fail header.i=@*****ech .com header.s=mail header.b=“cl/tUbWI”;
spf=pass (google.com: domain of support@***ech .com …

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=***ch .com; s=mail; t=1700909023; bh=g3zLYH4xKxcPrHOD18z9YfpQcnk/GaJedfustWU5uGs=; h=Date:From:To:Subject:From; b=cl/tUbWIWu4LFtWIYhrkZAgfArfnhX1W/BdhBFCjhmY40T47zwJ/VTkSINraXyto5
4ITn8EDNgrBE2hUW1qI/XqkGl1o0cOoDc4O81iDJUatCq1drRiWbZ+FyxsiBmS3JfE
N2QMXHHTrj2aCV2uvkhrhmn+8zqAjV++Lef15ay8/MMSSG6Cmb+mrQGrd+hKXn2EmX
qfGg0dMXZ9K6MXhOKorNJzJo/Oo5RRT0/g31CAmm ************

When i remove sendinblue enteries in Cloudflare DNS record, DKIM error go away and mail is signed by domain appears.

So here both sendinblue and mailinbox using same names mail. _domainkey
is the error because of this???
we can change anywhere or any suggestion please, I try many things but it doesnt work.

2

Yes. I suggest contacting Sendinblue and asking if they have an alternative DKIM selector that you can use.

Alternatively, you can quit using MiaB or Sendinblue.

3

Thanks @alento I contacted Sendinblue and there they have 2048 bit hostname with different name so one has to request through support to change from mail. _domain .key to sib2k. _domain .key and now its working.

So my question now is there anyway in MiaB to change their hostname for DKIM if needs arise. From mail to some other text?

4

It could be done, but it would be an unsupported modification and so outside the scope of the project that I am 99.9% certain that it would never be considered for inclusion. Especially with the lack of developers the project has now.

5

It would have been better for future developers in case anyone would note that not to use “mail” as DKIM hostname, simply named it differently, so no change required.