Going to spam

hi @ljhelbo

I would add webserver IP in the SPF record https://www.whatsmydns.net/#TXT/hammeltennisklub.dk

v=spf1 include:spf.simply.com ~all

Then

v=spf1 include:spf.simply.com ip:93.191.156.64 ~all 

Otherwise you can use any plugin as WP SMTP

Cheers

Adding to Jairo’s suggestion, because one small typo there would make things worse:

1. The SPF mechanism for an IP address is ip4:, not ip:. Edit the existing record (don’t add a second v=spf1 record, two records break SPF) so it reads:
v=spf1 include:spf.simply.com ip4:93.191.156.64 ~all
This matters on your domain because its DMARC policy is p=reject, so mail that fails both SPF and DKIM can be refused outright, not just filed as spam.

2. In the form’s Mail tab, set From to an address on your own domain, e.g. Hammel Tennisklub <wordpress@hammeltennisklub.dk>, and put the visitor’s address under Additional headers as Reply-To: [your-email]. If From is the visitor’s own Gmail or Hotmail address, the receiving server sees “Gmail” mail coming from your web server and treats it as spam whatever your SPF says.

An alternative to step 1 is to send through your host’s mail server with an SMTP plugin and a real mailbox on your domain. That mail is already covered by include:spf.simply.com.

To see exactly which check fails, send one form message to the address mail-tester.com gives you. It scores SPF, DKIM and DMARC separately.