outlook email won't allow sending to hotmail addresses

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AAC

23 posts

Geek

#318625 4-Feb-2025 20:58

I can no longer send emails to people who have hotmail.com email addresses

I am using my snap email account and also a netaccess.co.nz email to send out the emails on snap's smtp and port 25

I am using both MS outlook desktop versions 2019 on one pc and 365 for business on the other. This issue only started happening today.

Both Outlooks give me the same error. And it only gives me the error when I am sending to anyone with a hotmail email address.

I contacted Two degrees it will take them a few days to investigate, but they only provide support for emails on their webmail platform.

So I contacted the IT people who provide us with the MS 365 via Spark and they did not have a clue.

Any ideas would be great.

Here's part of the error. (I removed our WAN IP)

This is the mail system at host pmg-2.snap.net.nz.
I'm sorry to have to inform you that your message could not be delivered to one
or more recipients. It's a􀆩ached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can delete your own text
from the a􀆩ached returned message.

The mail system

hotmailemail@hotmail.com>: host
hotmail-com.olc.protecƟon.outlook.com[52.101.68.1] said: 550 5.7.1
Unfortunately, messages from [xxx.xx.xxx.xxx] weren't sent. Please contact
your Internet service provider since part of their network is on our block
list (S3150)

freitasm

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#3339359 4-Feb-2025 22:15

Which SMTP are you using to send these emails?

Outlook/Microsoft 365 has nothing to do with this.

Rickles

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#3339472 5-Feb-2025 09:58

I've encountered this at random times ... seems that MS mail servers are often blocked for spam etc by ORB or another blocking service.

Last line of error message suggests this .... usually comes clear after a few hours.

Rickles

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#3339475 5-Feb-2025 10:03

.... or MS has blocked your email service provider due to reported spam.

It's hard to tell who is doing what to whom in these circumstances as error messages are sort of standard response.

My emails to my daughter's Outlook and Live addresses occasionally get bounced like this and each service blames the other 😬

freitasm

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#3339478 5-Feb-2025 10:05

The last line suggests to me that the OP is using the Outlook client, connecting to the Snap emails servers, from a different ISP.

Hotmail is blocking either the Snap email server or the OP's IP address.

The OP will need to answer my question so we know what's going on.

In any case, it's not a Hotmail problem.

KiwiSurfer

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#3339541 5-Feb-2025 11:07

The error message seem to suggest Snap's on Microsoft's block list for some reason. This is something 2degrees need to look into -- I suggest you contact 2degrees and log a fault with them.

AAC

23 posts

Geek

#3343235 15-Feb-2025 17:42

Thank you for your comments.

It did clear itself the next day.

Two degrees never came back to me.

Our ISP is two degrees and the smtp is smtp.snap.net.nz on port 25

We are using a netaccess.co.nz email address for sending out emails. Its an alias of one of our @snap.net.nz email accounts.

Snap (2Degress) don't support their emails on third party email applications.

Rickles

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#3343238 15-Feb-2025 17:53

@AAC ... pleased it came clear.

This might explain matters ...

Email Blacklisting Explained: Causes, Impacts, and Solutions

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KiwiSurfer

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#3343279 16-Feb-2025 09:31

AAC:

Snap (2Degress) don't support their emails on third party email applications.

It was nothing to do with your application in this case, so they should really have followed up IMHO. But glad it cleared itself up.

AAC

23 posts

Geek

#3343298 16-Feb-2025 11:35

For the most part the emails work without incident. Sometimes emails will get held up for several hours but its not a regular occurrence.

I had asked two degrees if they could release the netaccess.co.nz domain so I could purchase it, but they said they still have customers using it.

In the early days of Snap they provided great support, and I very rarely had issues with spam.

Since they moved to Two degrees their support is not the same. But they still charge the customer for snap email addresses.

Would have liked to have known where the issue was, strange how it only affected hotmail email addresses. I hope it was just a one off.

TwoSeven

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#3343794 17-Feb-2025 18:22

Out of interest, the error message suggested that the destination mail server rejected the email, not the sending server. Also, more specifically, it was rejected due to mail delivery permissions - in this case, the sender was blocked from sending (the last part of the error code). Reading the original post, it appears one may be sending multiple emails, so that may have triggered the filter.

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AAC

23 posts

Geek

#3348953 1-Mar-2025 12:30

Hi All

Thank you for your suggestions. The incident happened again but this time with xtra.co.nz emails. Two degrees did finally come back to me and confirmed that the issues was due to ISPs blacklisting their IP address. They advised that they are sorting it. I can now confirm that the emails I now send to either hotmail.com or xtra.co.nz addresses do now reach their destinations.