I have a weird problem going on.
Whenever I send mails from my company's email account on PostBox (similar to Thunderbird for those that don't know) it ends up in the spam folder on the receiving end (Gmail, Hotmail, Yahoo etc).
But when I log into our hosting company's web mail and send an email from there (same email address), it ends up in the Inbox like it should (and not in the spam-folder).
I did a test where the body of the two emails were the same.
Any idea why this might occur?