Getting hotmail to accept emails from my domain

January 13, 2016 9:52 AM

Short version is, I can't send any emails to hotmail users unless they've emailed me first. The mail logs show that the mail was delivered though (queued for delivery). I've contacted them and they were no help - just the standard form responses about unsubscribe links etc - except we're not sending junk mail. This is just a person sending an email to another person.

We used to be on a shared server which was used to send spam - not from our domain but from the same IP. We started to have problems sending emails (but ironically had no problem with hotmail!) so we decided to migrate to our own mail server.

Since then, any emails sent to hotmail just aren't getting through. I'm running pretty much the same setup as I do on my personal server (and actually put a lot more work into this one - DKIM, SPF, PTR etc). Emails I send from my personal server get through (but go into junk), emails from the team server just disappear into the ether. They don't bounce but they don't arrive. The mail logs report the same on both servers - sent=ok mail queued for delivery

I just don't know what to do to get these emails through. The mail server is for an amateur sports team and a lot of our members have hotmail accounts but I can't email them unless they've emailed me first and it doesn't matter if they've emailed a different account either. For example, new members start by contacting our recruitment co-ordinator but when they're eligible for membership, I email to invite them and it doesn't get through unless they email me first, even though my colleague has been emailing them from the same domain.

posted by missmagenta to Computers & Internet (7 answers total)

It's hard to diagnose this sort of thing from a description, but here are a couple of things to look at:

1) Are you sure your SPF record is configured correctly for your domain? If your colleague can send email, but you can't, the difference might be in the SMTP servers you're using. If you're using different ones, you need to make sure that both are included in the record.

2) Look for anything that might flag a spam filter in features that are common to your outgoing emails, like your signature. Image tags, links to domains that might appear on a blacklist, improperly formatted links that might accidentally be classified as phishing attempts, that sort of thing. Again, if this is the problem it will be something different between your colleague's emails and your own. Sometimes it's something that doesn't really make sense. I once had to do some troubleshooting for someone who only managed to outwit a filter for a particular recipient by slightly changing the default font on his email.
posted by figurant at 10:44 AM on January 13, 2016

Response by poster: With my colleague, people email her and she replies - she the first point of contact for the team. I tried her account and the message didn't arrive either. Once a hotmail user has emailed a user on our domain, that user can email them fine but other users can't, unless that person also emails them.

The DMARC reports say the spf is fine and mxtoolbox.com says its all ok.

I've no email signature. At the moment I'm just trying to get a basic Hello World message through. I've tried both my email client (thunderbird) and the webmail (Horde) so I don't think its a formatting issue. The domain name contains the word Harlots but we didn't have this problem until we moved to a new mail server.
posted by missmagenta at 11:19 AM on January 13, 2016

Try setting up a mailgun account and sending from their API. I moved my company's outgoing automated email to this service and it works well. If nothing else it will help you troubleshoot (because if mail via mailgun works then it's something about your setup, whereas if it doesn't then it's something about your senders).
posted by axiom at 11:40 AM on January 13, 2016

It doesn't sound like it's a content issue, especially if you're just sending non-HTML test emails through Horde. DMARC inspection will tell you if there are any issues with the domain records, but it can't tell you anything about issues with the sending path, headers, or signing on outgoing emails. You may have already done this, but you can send a test email to an automated verifier listed here.

It sounds like all the email that's getting through from you is after an initial contact from a hotmail account. I see there are a few other reports around from people who've encountered the same issue. Other than going through a major third party email service (like mailgun, mentioned above), which you may not want, there might not be an easy way around this. Hotmail is understandably very aggressive about spam, and doesn't seem to care too much about false-positives.
posted by figurant at 11:42 AM on January 13, 2016

Google started to not accept emails from me and when I started to dig into it, I found out that the canonical address for my mail server's IP did not match the domain I was sending from (because I was sending from my phone company's fiber service)

That is, I was sending as if my mail server was foo.com, which resolved to, say, 10.0.0.1, but when google did a reverse lookup on that IP, they got something like dynamic-ip-10-0-0-1.att.net and concluded that I wasn't "really" foo.com
posted by RustyBrooks at 11:56 AM on January 13, 2016

Response by poster: https://www.mail-tester.com gives me 10/10 and says the message is DKIM signed. Port 25 says
SPF check: pass
DomainKeys check: neutral
DKIM check: pass
Sender-ID check: pass
SpamAssassin check: ham

All I've found from googling is that its the new server IP doesn't have enough of a reputation but I can't do anything about that. How can they just reject all mail from new mail servers without giving us any means of rectifying it. We've had this new mail server and not sent any spam from it for 6 months.
posted by missmagenta at 1:52 PM on January 13, 2016

You might also find this help article from Microsoft for troubleshooting issues sending to Hotmail/Outlook.com useful.
posted by Aleyn at 8:55 PM on January 13, 2016