The from and the to address are not the same, and the from address is valid.
The return address is firstname.lastname@example.org. Would that trigger the email to be treated as spam?
I looked at the header, and there was a lot of gibberish. I noticed this though "email@example.com does not designate permitted sender hosts". Maybe you could say more about the header info, if I forwarded it to you.
I ran some more test:
- Both gmail and yahoo mail will put the mail into the spam folder.
- I removed all links and images, basically left only one sentence, and it would still go in the spam folder.
- and most troublesome, our order confirmation mail also goes right into the spam folder
I also talked to our internet provider and he said, that yahoo and gmail may block html mail altogether. But they have clients on the same server as ours, that successfully send newsletters, because their newsletters come in html and text. Does WebAssist offer a solution, where a text mail is offered, if html mail is refused?