Dienstag, 4. Dezember 2018

Mails not sending to outlook.com or hotmail.com from own Mailserver

I've had the Problem that Microsoft Servers didn't accept my Mails from my server so I made DKIM and SFP-Records but that also not suceeded. So I read through the internet and found a lot of posts of frustrated admins and even ISPs with the message: Microsoft don't care about delivering mails due to the standard - the Mails are send, the code is ok but with no response they fall in the black hole and have never seen again.

https://twitter.com/search?f=tweets&q=hotmail%20blackhole&src=typd
https://www.akeyes.co.uk/blog/hotmail_com__outlook_com__live_com_blacklisting____a_pleasant_experience

So what to do? As company you can't really tell your customers to change their mailadress so they can get mails from you (we advising our customers to this but as IT company thats our job ;) ).

As mailserver owner you can register to Sendersupport / SNDS Service from outlook. There you can verify your own IPs and can manage them if they are on blocklists. As far as I got after checking all those mentioned points at https://sendersupport.olc.protection.outlook.com/pm/troubleshooting.aspx and your ip on https://sendersupport.olc.protection.outlook.com/snds/ipStatus.aspx

You also have to mail your request over this form
http://go.microsoft.com/fwlink/?LinkID=614866
(mind there are only 2000 chars allowd in the description box!) . Then you get a mail you have to confirm and then your IP is whitelisted. This lasts for one of my servers for over half a year now but some users reported that after a few weeks/months MS is again blocking emails. I think this could depend on the emails sent from the users of your Server so as anybody marks them as Spam Mirosoft will block it again.