Situation: I am sending emails from me@mydomain.com
to alice@example.org
. My DNS for mydomain.com
is correctly configured with an SPF record. The recipient at example.org
is able to receive my emails just fine (it says "SPF: pass" in the headers).
Now, Alice configures alice@example.org
to redirect any email to bob@otherdomain.com
. So alice@example.org
no longer has a mailbox or account attached to it, it's simply a forwarding address to bob@otherdomain.com
.
I send an email to alice@example.org
again. However, the receiving end at otherdomain.com
now thinks the email is coming from example.org
(as that's the last forwarding server or IP address), which of course does not have the SPF record that I have on mydomain.com
. So it now marks my emails as failed for the SPF check, and puts in the spam folder.
So in short, the problem is: Due to redirecting email (on which I have no influence) the final recipient erratically thinks my email fails the SPF check, and discards it as spam. Is there a way to avoid this?
Also, I noticed sometimes that if I don't have a DKIM record (and not using DKIM) but the forwarding server does, then the recipient thinks my message failed the DKIM check as well. Whereas I don't even use DKIM, nor do I have a DNS record for this. It's the forwarding server (example.org
in this example) that makes the recipient think the email should be DKIM signed.
(edit) Note that if I email to bob@otherdomain.com
directly, the problem does not occur. My email is then considered to be valid (it passes the SPF check) and does not get filtered as spam. However I can't know in advance if someone is using a forwarding address.