Can't send email from droplet to to some servers,others are OK

Posted January 2, 2015 6.4k views

I’m using postfix and cyrus which I set up as directed with mixed results. Yahoo and Gmail handle my emails well. Hotmail put it in the spam folder but doesn’t after being notified it’s not span. I tested by reading maillog after an attempt to send mail from DOserver to my roadrunner email account and observing maillog.
Here is the maillog entry:
Jan 2 06:10:55 Hanksite postfix/smtp[20314]: 49C48609ED:,[]:25, delay=15,
delays=0.02/0.01/15/0, dsn=4.5.4, status=deferred
refused to talk to me: 554 5.5.4 Relaying denied.
IP name lookup failed for myIPaddress)

It looks like they can’t get through my smtp port. Why don’t the other major servers have the problems ? How can I fix this?

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3 answers

I have never set up any mail servers before, but anyway:

Do you have a reverse DNS entry so it is possible to look up the domain name from the IP?

  • @flexd
    Thanks for the reply
    You may be right. The maillog shows the remote server trying to do a reverse DNS Lookup and failing. I’d make a reverse DNS entry DNS table, but DO’s control panel doesn’t seem to show how.

  • @ralper3 The DNS control panel says: “To update your PTR record please update your Droplet’s hostname through the control panel.”

    So update the droplets hostname to the proper domain and it should set up the reverse DNS entry.

  • @flexd
    You were right about the reverse DNS entry. But as I noted previously, The control panel is not clear about how to do this. I prepared a support ticket. and received instructions. Problem solved!
    See my post below.

If you’re new to DigitalOcean, they may be blocking Port 25. That’s pretty common and it’s a measure in place to prevent spam since the entry level is cheap (which spammers love).

To get that lifted, you’ll need to contact them via support ticket.

  • @jtittle
    Thanks for the reply. I have been getting out on port 25. Perhaps its blocked on incoming.
    I’ll try a support ticket.

  • @ralper3

    Have you setup your SPF & DKIM TXT (DNS) entries for your domain? If not, that is something you will need to do as any major provider will automatically reject your e-mails if they’re missing.

    I’ve had this experience with Google, Yahoo, RackSpace and a few others. I’m sure Microsoft and the Outlook service does the same as it’s just easier to reject them than to allow them to come through and deal with the potential spam-storm.

  • @jtittle
    I have had a reverse experience. I could reach Hotmail, Yahoo, Earthlink and Gmail. I couldn’t reach Bell South, AOL and several smaller providers. Nevertheless, problem solved with reverse DNS entry.
    See my post below.

Problem solved with reverse DNS record. This is also known as a PTR record. Checked with support and P. Singh indicated that the PTR record is automatically set to the droplet name. You must therefore change the droplet name to your domain name.(i.e. To change the name of the droplet : Go to the control panel and select droplet. Then click on your droplet’s name. Next select Settings from the horizontal display of choices.(Ignore the Settings choice in the main vertical menu) Then select Rename and type in the new name.