I sent a modest amount of bulk email via Mailgun.
When I looked at the mailgun dashboard https://app.mailgun.com/app/dashboard I saw that some failures had been recorded.
I went to the
logs page and saw more detail. It seems that some of the recipients' mail servers (particularly Microsoft ones, e.g. live.com, outlook.com, hotmail.com) refused to accept the email and said:
"code": 550, "message": "5.7.1 Unfortunately, messages from [18.104.22.168] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [HE1EUR02FT024.eop-EUR02.prod.protection.outlook.com]"
When I tested that ip address at https://mxtoolbox.com/blacklists.aspx
...it said I was on a few blacklists
We notice you are on a blacklist. Click here for some suggestions Checking 22.214.171.124 against 93 known blacklists... Listed 4 times with 3 timeouts
A blacklist, alternatively called a DNSBL(DNS blacklist) or RBL(Realtime Blacklist), is a spam blocking list that can prevent a mail server from sending email.
Details for one of those lists said:
Reason for listing - MTA-Pro Blocklist, visit dnsrbl.org for removal - IP Address: 126.96.36.199
I visited that page and found:
Query Results Spam history for 188.8.131.52 (times in UTC): Sun Mar 4 11:40:13 2018 spamtrap hit Mon Mar 5 17:45:51 2018 removed from list Mon May 7 08:50:06 2018 spamtrap hit Fri May 18 05:14:19 2018 removed from list Tue Jun 5 23:10:03 2018 spamtrap hit Remove IP from DNSRBL 184.108.40.206
I clicked on "Remove IP from DNSRBL"
Removal Results IP address 220.127.116.11 has been removed from the database. It should be gone from DNSRBL after the next zone file rebuild, in a couple of minutes. Note that it will be added back the next time it sends email to one of our spam traps.
And I found...
More information about Hostkarma Black can be found at their website: http://wiki.junkemailfilter.com/index.php/Spam_DNS_Lists Reason for listing - Black listed at hostkarma http://ipadmin.junkemailfilter.com/remove.php?ip=18.104.22.168
I go to the removal page...
Note: This is a courtesy removal form for those who were either wrongly listed or have fixed the problem and is now ready to be delisted. IP address 22.214.171.124 returned DNS result code 127.0.0.2. 126.96.36.199 is Black listed - Click the Search Button Next - then you will get the Remove button. Don't email us about being removed. Just use this form. Your reverse DNS is correct! - mail16.static.mailgun.info The IP address for the reverse lookup name matches the original IP - RDNS Information This is a list from our log files showing the activity from IP address 188.8.131.52. Our system stores information for 4 days. /ip-log/karma.log.16:black 184.108.40.206 QUIT MULTI-BLACKLIST - [S=3 - hostkarma.junkemailfilter.com] - DOB-SENDER BlList - ID=04559-24370 X=pascal H=mail16.static.mailgun.info [220.127.116.11]:26010 HELO=[mail16.static.mailgun.info] SN=[bounce+a75798.83d79-cherylh=mpropertiesinc.com@justflowe
I clicked the remove button....
IP address 18.104.22.168 has been scheduled to be removed from the Hostkarma Blacklist. (Generally takes 5 minutes but if others cache the lookup it might take longer to take effect.)
Next I tried to clear us from SORBS...
More information about SORBS SPAM can be found at their website: http://www.sorbs.net/lookup.shtml Reason for listing - Spam Received See: http://www.sorbs.net/lookup.shtml?22.214.171.124
After entering a captcha I found:
Problem Entries, (listings will cause email problems.) 9 "Spam" entries [12:44:27 16 May 2018 GMT+00]. 126.96.36.199 - 9 entries [12:44:27 16 May 2018 GMT+00].
I couldn't delist there because:
An account is required to proceed!
After attempting all of the above I decided to contact mailgun support.
As a preliminary (before lodging a ticket) they said to first try mail-tester. https://www.mail-tester.com/
This was a good service! They gave me a score of 10/10 though. (Not sure I deserved it)
And had this helpful advice: You're not fully authenticated You do not have a DMARC record
A DMARC policy allows a sender to indicate that their emails are protected by SPF and/or DKIM, and give instruction if neither of those authentication methods passes. Please be sure you have a DKIM and SPF set before using DMARC. You do not have a DMARC record, please add a TXT record to your domain _dmarc.yourfirstproduct.com with the following value: v=DMARC1; p=none Verification details: mail-tester.com; dkim=pass (1024-bit key; unprotected) header.d=mg.yourfirstproduct.com firstname.lastname@example.org header.b=ekymBOx4; dkim-atps=neutral mail-tester.com; dmarc=none header.from=yourfirstproduct.com mail-tester.com; dkim=pass (1024-bit key; unprotected) header.d=mg.yourfirstproduct.com email@example.com header.b=ekymBOx4; dkim-atps=neutral From Domain: yourfirstproduct.com DKIM Domain: mg.yourfirstproduct.com You're listed in 1 blacklist Listed in SORBS (last 28 days) ( -0.5 ) Your message does not contain a List-Unsubscribe head The List-Unsubscribe header is required if you send mass emails, it enables the user to easily unsubscribe from your mailing list. Your message does not contain a List-Unsubscribe header
And this confusing advice:
Your message could be improved Weight of the HTML version of your message: 1KB. Your message contains 75% of text.
So I could add DMARC and potentially add a List-Unsubscribe header. I hadn't heard of that before. So it's good to learn about something.
I looked into how this is done, and it's not as simple as it ought to be. Given that I have a unique https'd URL they can 'get' to be unsubscribed, I thought it's just be a matter of feeding this to a parameter of the API call for mailgun. But alas, they want to "add value" by managing the unsubscribe functionality.
Here's the ticket I raised at https://app.mailgun.com/app/support/new:
Hello I would like to request: IP rotation due to blacklisting IP: 188.8.131.52 Message: 5.7.1 Unfortunately, messages from [184.108.40.206] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [HE1EUR02FT024.eop-EUR02.prod.protection.outlook.com] I checked at mxtoolbox and found the mailgun IP on 4 separate blacklists. This pre-dated my sending of emails, it goes back weeks and weeks. I tried to get it unblocked from all of them. I may have succeeded with 2, but couldn't succeed with all of them. please rotate my IP address if possible. Is there anything I need to do on my end, with DNS etc? kind regards Leon Bambrick
...And I attached the images from above.
This may have been overkill, by about 1000% percent, but I don't want to have to email them twice. And since I'm recording what I wrote I can reuse it later.