Custom domain Meet invites from mailbox.org with Proton MX: SPF/DKIM/DMARC?

Sebastiaan ten Broek shared this idea ago

Proposed

I currently keep MX on Proton for incoming mail, but I’m considering mailbox.org Calendar + Meet and I want meeting invites to be sent from there info@mydomain.com. with reliable delivery. I can add SPF records, but the key question is whether mailbox.org can DKIM-sign outgoing messages as d=mydomain.com (and ideally align SPF/return-path as well) without switching MX away from Proton, so invites pass DMARC consistently; if this is supported, can you tell me the exact setup steps and DNS records (SPF, DKIM selector/value, DMARC) needed?

this was my setup in google workspace and it works there but I want to ditch google and am lost king to see if mailbox can replace it for me

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Replies (1)

TeCer ●

you must add your email address info@mydomain.com as an alternative sender (email addresses -> alternative senders)

Add the mailbox.org DKIM records to your domain's DNS records (do not remove the existing ones) and add mailbox.org as a permitted sender in your SPF record.

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Sebastiaan ten Broek ●

I understand that. But I am looking for confirmation if Mailbox will let me use spf and DKIM without MX?

Can you confirm this?

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zapata ●

Yes, otherwise alternative senders wouldn't work properly. But I am not sure if Meet invites will only work with your main account address. AFAIR, there are some issues with e.g. the calendar.

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Sebastiaan ten Broek ●

Well looking at the docs they seems to offer relay without any dns set up. Not even mentioned and they also say relay is not recommended because it naught be spam blocked. That makes me doubt if they use it with dns or not.

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TeCer ●

I have an alternative sender configured. I use it rarely, but the emails sent always have DKIM aligned.

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Sebastiaan ten Broek ●

Thank you. That is some confirmation. I will just try it for my set up.

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