Yahoo (particularly when providing services for BT) silently delete some spam, even mail with a raw SA score < 1.5.
And they don't respond to complaints, even from their own users.
I've been running the same pukka mailing list for 12 years, I'm in their abuse feedback loop, have proved exclusive ownership of the mail server, all mail is DKIM signed with valid SPF records, mail is accepted with a 250 OK, you name it.
Still they bin my emails, but only to some accounts. No rhyme or reason, no bounce, no spam folder. Just never arrives.
And they don't respond to complaints, even from their own users.
I've been running the same pukka mailing list for 12 years, I'm in their abuse feedback loop, have proved exclusive ownership of the mail server, all mail is DKIM signed with valid SPF records, mail is accepted with a 250 OK, you name it.
Still they bin my emails, but only to some accounts. No rhyme or reason, no bounce, no spam folder. Just never arrives.