Some emails from Slack via chat.wordpress.org get discarded before reaching the inbox

[tobifjellner]

Notifications from Slack that are forwarded via a virtual address on the chat.wordpress.org domain get discarded by some email providers that check SPF and DKIM more thoroughly.

One of the best know domains that recently raised the bar is hotmail.com.

We should consider replacing the FROM address to and address in our "chat" domain.

This also means that our server can't just forward these emails. It will need to also recalculate the DKIM key (I suppose). So this isn't a trivial, change, but still quite urgent.

Here is one example:
​https://make.wordpress.org/polyglots/2025/10/19/pte-request-for-academylms-plugin/#comment-302929

[dd32]

@tobifjellner Do you have any information on what you're seeing here? Other than people suggesting they're not seeing the emails?

Correctly configured email forwarders can forward emails without issue, infact, DMARC is especially helpful here as the SPF doesn't need to pass in order for the email to be forwarded. As long as they don't alter the email contents / headers.

In the case of emails from Slack, they're passing through our forwarder and Gmail is showing it as fine.

I've just tested with a Outlook.com.au email address (aka Hotmail) and ALL emails from WordPress.org are being filtered to spam, but it shows DKIM and SPF passing (Both on the original Slack contents, and on the forwarded signature).

Changing the From on these emails would likely cause extra issues, as we'd have to strip out the Slack email signatures, and we'd likely hit spam filters thinking it's a phishing email (since the headers say it's not a slack email, but the contents says it is)

[dd32]

gmail passing DMARC

[dd32]

Outlook headers showing signature pass

[lubostomicek]

Hello. I am trying to register for wpcz.slack.com - Czech WP translations community. I am using lubostomicek@ chat.wordpress.org for registration. I am supposed to get an email with login codes forwarded to the email I am registered with aka. lubos@ lubostomicek.com. The emails never arrive. I whitelisted slack.com, chat.wordpress.org, and wordpress.org on my email server but still no emails reach my inbox.
I get emails with notices from wordpress.org without problems. But no emails from slack. I now tried to add the lubostomicek@ chat.wordpress.org to my Gravatar profile and again, no email received on my registered email lubos@ lubostomicek.com.
That means either there is problem with forwarding to my email or the email is blocked by on my email server by some process I have no idea about.
Any help would be appreciated.
Lubo