Firstly thanks for the fork, I have been looking for a solution to configure MIAB to relay outbound emails via 3rd party service due to port 25 being blocked on pretty much all major cloud service providers.
Now, I have installed your Power-MIAB on a vm on GCP and attempting to configure email relay via Sendinblue. There are some issues I came across that prevented me from completing the relay configuration, I wonder if you could shed some light on them.
Sendinblue requires setting DKIM record mail._domainkey.example.com to the value they specified. I cannot however do it because MIAB has already setup this specific record. When I attempted to set the mail._domainkey.example.com in “SMTP relays” page, I got error message that “mail._domainkey.example.com” has already existed and cannot be modified.
Sendinblue requires setting DMARC record _dmarc.example.domain to a specific value. Your “SMTP relays” web page doesn’t provide any mean to configure it. And again MIAB has already configured its own DMARC record which I suspect again won’t let me change.
In short, Sendinblue requires configuring DKIM, SPF, DMARC and one additional TXT records as per “Customise your DKIM signature”. your “SMTP relays” web page only allows configuring SPF and DKIM, missing the DMARC. Plus it appears that user cannot change what MIAB has already configured, specifically the DKIM record mail._domainkey.example.com and DMARC record _dmarc.example.com.
Update after I changed 3rd party SMTP relay service from Sendinblue to Mailjet
I signed up with Mailjet for testing purpose, also because they allow 200 emails per day on free plan, same amount as Sendinblue.
Funny enough, Mailjet only requires two DNS records to be set, the SPF TXT record and DKIM record. More importantly Mailjet don’t insist on creating the mail._domainkey.example.com DKIM record, instead they require mailjet._domainkey.example.com DKIM record, which doesn’t clash with what MIAB has already put in place. Therefore I was able to configure the DKIM record correctly.
Configuring the SPF record however wasn’t as smooth. David, your “SMTP relays” web page doesn’t allow me to manipulate the SPF TXT record myself, rather it asks me what sender’s domain should be included, then I guess you have script behind the scene to configure the SPF record based on the input. This didn’t work well for me. Specifically I needed the SPF record to be:
v=spf1 include:spf.mailjet.com mx a:spf.mailjet.com -all
What I could do on the “SMTP relays” web page was to enter “spf.mailjet.com” into the section named “Add your SPF configuration/authorized servers here”, then your script will setup the SPF record as:
v=spf1 mx a:spf.mailjet.com -all
I tried many times and could never get it to put the “include:spf.mailjet.com” part into the SPF record.
At the end I had to create a custom DNS record that matches what was required by Mailjet, and it has started working since.
end of update