Post #4232861
2026-07-01 10:19 UTC
@Bibliothecaris@social.edu.nl We can't provide direct feedback for these products but we have been running and are running our own outgoing SMTP server for years now. Contrary to popular believe it works even with MSFT, Google and other email providers. You have to have SPF, DKIM and DMARC correctly set up. There are important details like the reverse DNS entry of the sending IP matching all this and so on. But it is doable. There are free services to test your setup and provide valuable feedback.
Replies (2)
-
@Bibliothecaris@social.edu.nl 2026-07-01 11:12
@TobiasFrech@ijug.social Interesting, thanks!
-
@vince@infosec.exchange 2026-07-01 18:22
@TobiasFrech@ijug.social I’m curious about your ip space. Are you using a cloud provider or your own allocation? I haven’t bothered in a decade, but at that time both ms & google were intermittently blocking fully compliant (fw/rev dns, spf, dkim, dmarc) for no apparent reason - it was source address, most cloud providers were on the block list. Most egregiously, they’d accept it at the ingress and drop it somewhere else in the chain without the recipient/sender ever knowing. With the tracing in 365/gmail now, that practice may have changed.