Outlook.com not receiving emails sent from my Digital Ocean droplet

September 14, 2015 3.5k views

Hello all,

I am running Ubuntu 14.04, my mail server is dovecot 2.2.9 and postfix 2.11.0 is the mail transport agent.

I am having an issue where the mail server successfully sends email notifications to the likes of gmail and yahoo but we fail to get any mails to outlook.com email addresses.

We have checked for being blacklisted, which we are not. I have seen other posts with similar issues but no one coming back saying that they have sorted this issue. Surely someone has setup a DO mail server that can send mails to an outlook address. Any help greatly appreciated.

Many thanks

  • Are you the emails are not going to spam or being blacklisted all together. This can happen when sending emails from a mail server. Something like this might help http://www.extendoffice.com/documents/outlook/1129-outlook-add-safe-senders-list.html

  • Thanks for the response. I have checked a number of blacklist sites and the domaib and ip address have no problems. We are finding that it does not matter if we send an email from automation on the box or by a client like thunderbird sending emails, neither land to the outlook.com address.

    The only time where it has worked is when the outlook.com address has instigated the initial mail and i have responded to it… this is no good to us.

1 Answer

Allright, so the thing with Outlook is ; They want to keep out as much rubish as possible. Understandable, but sometimes that makes it difficult and annoying to properly setup your mailserver. Their firewall is very strict, and you don’t get ‘points’ easily. So you are being signed as spam or blocked fast. First of all, have you checked the spam? And if so (and the mail is inside), what does the source of your mail says?
Second thing you need to look at, if you would like to run a working 'professional’ mail server are authentication methods. Mailproviders like gmail, outlook, yahoo and more look at all these properties, and then determine if your allowed to get inside their system. You need to think about:

  • DKIM (DMARC to check your mail backlogs)
  • SPF
  • PTR
  • Blacklists (you checked already)
  • Open relay
  • IPV6
  • MX

Once you researched about these properties, you will know how to setup a mailserver and / or ask any more questions.

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