SPF: HELO does not match SPF record (softfail) in mail-tester.com - how to overcome it?

Question

SPF

I want to fix this SpamAssassin error from the mail-tester.com results:

the problem is that letters are sent from VDS via PHPMailer where hostname is one domain, and the mail domain from which the mailing is sent is completely different - although it is tied to this VDS

Answer 1

So write in the SPF record of your mail domain the name of the server that is passed to HELO.
mydomain.com IN TXT "v=spf1 a:sender.net ~all"