I maintain the monthly newsletter from our local chapter. To make life a bit easier I use Mailchimp (free version) for this purpose.
That is what they exist for ;-). But noticed that it didn’t received the newsletter anymore on my @on4aob.be mail address. Fyi ON4AOB is the callsign from our club. But I had no clue what was going on. I started by disabling the spam filter, no result. I added myself with a second email to the list. This worked. So the problem seems to be with the on4aob domain. In Mailchimp I didn’t found bounces or any other error records, so little to investigate on.
Few days go by without any solution. At work, adding a partners mail server to our DNS records opened my eyes. I had never added Mailchimp to our DNS records.
This lead to marking all mails form Mailchimp sent with an @on4aob.be address as possible spam and not delivering them.
The solution was adding the needed SPF record. Head over to Postmarkapp.com to find out what they are. In short : it allows a third party to send mails on your behalf.
My basic record was :
v=spf1 mx a include:webawere.nl -all
This will translates as :
- version 1 (SPF1)
- allow my MX record (Mail eXchanger)
- my own A record (ip of my hosting server)
- Webaware.nl (this is my hoster).
- -all hard fail, block all mail not authorized by this record
There was the problem, I never authorized Mailchimp on my side. Reworked the entire SPF record and waited to see what happens when the newsletter from december is mailed.
New SPF record :
v=spf1 mx a include:servers.mcsv.net include:webawere.nl ~all
So, servers.mscv.net is now included and I changed the fail from hard fail (-all) to soft fail (~all).
And yes it works!
Tools to check (your) record: