Hi Michael,

Before moving on, I’d like to clarify the situation.
1.Do you mean that an error report occured when you send email to an account hosted on Office 365 from your office 365 account: xxx@onezerone.com ?
2.The error report says that the IP address [204.93.182.115] was blocked by Spamhaus Blocklist, but your IP address not list in it.
3.Are you using SMTP Relay? Could you give me more situation about this issue?

I see that you received a Nor Delivery Report (NDR) after email sending failure. For further research, could you send me full details about it via private message. 
To request the NDR information, I’ve sent a private message to you.
To see the private message:
   1. Please go to "Your details" section on the right side of the community site.
   2. Click Private messages.
   3. Click the subject title of the response to read the message

Thanks,
Aaron Yuan

Hi Aaron, thanks for replying.

Let me answer your questions:

1) No, this was not an error that I received in email. My web app tried to send me a notification. I did not receive it, so I looked at the SMTP server logs and that is where I found the block. For some reason, my SMTP service did not send me an NDR. It never successfully sent the email to my Office 365 mailbox. It was blocked by the server CO1EHSMHS013.bigfish.com [216.32.180.190].

2) Yes, the server CO1EHSMHS013.bigfish.com replied with 550 5.7.1 Service unavailable; Client host [204.93.182.115] blocked using Spamhaus Blocklist, mail from IP banned; To request removal from this list see www.spamhaus.org/.../bl.

However, when I clicked the link for Spamhaus, it said my IP address was NOT listed.

3) No, my SMTP server is not an open relay. It is simply a local SMTP service designed to send email notifications from our web app. I have configured the SPF records to list this IP as a valid sender: "v=spf1 include:outlook.com a:fuse.onezerone.com ~all"

The only NDR that I received was when I was trying to send an email to postmaster@bigfish.com and postmaster@frontbridge.com about this issue. It is odd that you don't have a standard postmaster email to report these types of problems to.

Anyway, that's about all the information I can provide. Like I said, this just started happening yesterday. Thanks for your assistance.

Hi Michael,

Thanks for your update.

From your description ,I see that this issue just started happening yesterday, does it means that it works right before?

I’d like to know the what’s the sender address you use? 
Is it means that you send emails via a local SMTP server to the account in Office 365 ?

Based on current situation, If you use O365 E plan,I suggest you create an inbound policy rule in FOPE of Office 365 to allow the email from the sender.For details, you can refer to the link below.
http://technet.microsoft.com/en-us/library/ff715238 

Thanks,
Aaron Yuan

Yes, this just started happening. And it doesn't happen with all notifications, so it looks like some servers are using an invalid blacklist.

I looked through my logs and it appears that there is one server on your end that is blocking my emails. The rest appear to go through just fine:

The IP address of the blocking server is 216.32.180.190.

These IP addresses work just fine:

216.32.181.178

216.32.180.22

65.55.88.22

The sender email is fuse@onezerone.com which is from our web app. It's also an alias on my main account mcarter@onezerone.com.

We are on the P1 plan, so an inbound rule does not apply to us.

Anyway, if you could have one of your engineers look into why 216.32.180.190 erroneously thinks we're on the Spamhaus blacklist, that would be great.

Thanks!

Hi Michael,

From the description provided, the problem may be caused by FOPE blocking the IP address.
Please refer to the private message I’ve sent to you to get the detailed information.

Thanks,
Bourne Zhang
 

Hi Michael,

How are things going now?
Do you need more assistant about this issue?

Thanks,
Aaron Yuan

Hi Michael,

I’m glad to hear that the issue has been resolved. Thanks for your update.
 
Thanks,
Aaron Yuan