On 11/02/2021 11:53, Tim Streater wrote:
On 11 Feb 2021 at 11:07:18 GMT, Martin Brown
wrote:

If you check your domain name using nslookup you can see if they are
right. Incantation from a DOSBOX is:

NSLookup.exe -q=TXT nonad.co.uk

Mine looks like this: "v=spf1 include:spf.protection.outlook.com -all"

I'm guessing yours might come back "not found" or "none". The recipient
might well have your email but in some quarantine spammer junk mail box.

I tried this in a macOS Terminal window and got a similar line for a couple of
my domains, and "not found" for a couple of others (as you suggested might
happen). Perhaps that explains why I occasionally get an email from my ISP
saying that they have quarantined a mail as possible spam, but they'll send it
me if I really want it. And as you say, it doesn't really work worth a damn.


It isn't a great idea to be sending mail out that has SPF fail in the
headers since it results in plenty of corporate mail servers treating it
as spam or even worse dropping it on the floor without any notification.

I suggest you only use your domains with plausible SPF records for
sending mail and ask your ISP to sort out the ones that are defective.
(if you intend to send mail from them)

--
Regards,
Martin Brown