How to avoid Spam in Outlook/Hotmail with Mailgun?

Question

I'm using Mailgun to send transactional emails (tickets for events) and all the emails are sent to Outlook/Hotmail spam and I want to avoid that. I have added the SPF and DKIM records and nothing works. What should I do to avoid the spam filter (actually, I'm not sending spam. The user triggers the transactional email when he register to an event)

Client client = Client.create ();
client.addFilter ( new HTTPBasicAuthFilter ( "api", "MI_API_KEY" ) );
WebResource webResource = client
        .resource ( "MAILGUN_URL" );

MultivaluedMapImpl formData = new MultivaluedMapImpl();

formData.add ( "from", "[email protected]" );
formData.add ( "to", "[email protected]" );
formData.add ( "subject", "Camilo, welcome to the event" );
formData.add ( "html", "<h1>Camilo thank you for your registration in the event</h1>") );
formData.add ( "text", "Camilo thank you for your registration in the event" );

ClientResponse clientResponse = webResource.type ( MediaType.APPLICATION_FORM_URLENCODED )
        .post ( ClientResponse.class, formData );

int status = clientResponse.getStatus ();

if ( status >= 400 )
{
    throw new BadRequestException ( "Your message couldn't be sent" );
}

Answer 1

Your issue isn't your code, it a problem with using MailGun. If you check the email headers with the following site:

https://testconnectivity.microsoft.com/?tabid=mha

You'll see something similar to the following:

Spam Confidence Level   5 (Spam Confidence Interpretation - Spam)

Bulk Complaint Level    6 (Bulk Complaint Level - The message is from a bulk sender that generates a mixed number of complaints.)

The issue is that MS view anything from a shared MG IP as coming from a bulk sender, this impacts SPL and can raise it to 5 or above (spam).

How do I know this? I'm having the exact same issue. I think the only option will be to go for a private IP, but our sending volume is not high enough, so it looks like we've wasted a lot of time and effort on MG!

Does anybody know another bulk sender that avoids Hotmail spam?

---

OK, an update to this just in case it helps anybody. We have finally managed to get delivery to Outlook from MailGun, this is what we checked / corrected etc, hope it helps:

• From address needs to be [email protected], not [email protected] (seems obvious now, be we missed this
• Add a h:List-Unsubscribe header and use <%unsubscribe_url%> to substitute the unsubscribe link
• Check your SPF. When adding the MailGun SPF our provider added an additional invalid SPF record automatically, apparently you can only have one SPF per sub domain
• Make sure that links in your content link to your domain
• Make sure that branding is relevant and links to your domain
• Make sure you have a clear unsubscribe message. We initially just had a text link saying 'unsubscribe", we changed this to "Click here to unsubscribe if you no longer want our emails"

It is definitely worth checking the headers with https://testconnectivity.microsoft.com/?tabid=mha This will give you leverage when getting MG to switch out an IP with poor reputation.