Hi,
I'm Nicolò and I work in the deliverability team of Qboxmail.com. We have run into similar problems in the past. The reason of the behavior of Gmail with your domain is not easy to understand, a theory could be that in the past someone has used it for sending spam, and even if it was not your server, you are paying for this.
The solution we have used, it was bring Gmail to understand that your emails have been sent from a real user. You can simulate a conversation between your domain and other Gmail accounts. Send a first email, with a realistic text, to a Gmail account, if it goes in spam, mark as safe (remove it from spam), and reply to it, always with a realistic text. Continue to simulate a normal conversation, sending 4/5 emails between the 2 account. Re-do the operation from another Gmail account, but this time do the opposite:
start from the Gmail one.
It not bulletproof, but it has worked in the past for us.
You send emails that Gmail looks wrongly like spam. If everything is clean, it is reasonable to think that it is matter of little fixes, and to "help" Gmail to understand that domain doesn't send spam.
There is no way that this method would work id the domain it does actually send spam mails.
Sending about 250,000 emails per month for over a year now (all double optins), we found out that both gmail and yahoo has what we call "do you listen" rule.
Basically even if user expressly add you to their contact list and pull you out of spam, etc, if you sending them just your email ignoring what they reply back to you, eventually you get back to spam. I think this is very clever and is based on simple human rule that most follow when conversating over email: when people reply to email the do not start a new email, they hit reply and previous email from their convo lands on the bottom of this new email.
Once we started emailing new emails with adding content from addessee previous email to the bottom, our emails start getting back to addressee major mailbox.
And this make perfect sense on how to detect a real conversation (gmail has your sent items so if incoming email contains something you wrote before, its an indication you have a real live conversation with someone)
exactly. That is spam detection programs work. If you re-train them, when they think that the volume of spam sent from that domain in acceptable and normal, they will let its email pass.
Interesting - I cannot access this website because the domain is blocked by my company. We have 2 enterprise blacklist solutions to stop people from going to websites they shouldn't.
It is a problem with the policies of your company. I don't know why they should have blacklisted our site, maybe they want to be sure that your email are managed by them :)
If you are curious, try to go on our italian website: qboxmail.it
Sorry, I was referring to the bitbin.de domain from which this post is written. I was providing vague proof that the domain's history may have caused it to be blacklisted.
The solution we have used, it was bring Gmail to understand that your emails have been sent from a real user. You can simulate a conversation between your domain and other Gmail accounts. Send a first email, with a realistic text, to a Gmail account, if it goes in spam, mark as safe (remove it from spam), and reply to it, always with a realistic text. Continue to simulate a normal conversation, sending 4/5 emails between the 2 account. Re-do the operation from another Gmail account, but this time do the opposite: start from the Gmail one.
It not bulletproof, but it has worked in the past for us.