Hotmail Email

Question

Hotmail Email

Sierra Pappa 0

I'm having a few issues with email aliases.

Three times in the last 10 days or so, I have used my email address with a different alias for different website registrations e.g. example123+microsoft at hotmail.com and the email does not come through to me. This is not happening for all emails but is becoming more regular.

But recently, whilst testing an application I'm building, I integrated with a CRM system, added all the usual DKIM, DMARC and SPF records. Initially, emails were being received to my Hotmail account but now, I'm not receiving them at all. In my CRM, the emails are being tracked as 'Delivered' but there's nothing in my inbox or in Junk.

Any ideas from anyone?

Sierra Pappa 0 Reputation points

2026-08-03T19:03:50.0833333+00:00

Looks like the dummy alias I used as an example was obfuscated.

I mean example123[plus symbol] [at] hotmail.com

1 answer

Your answer

Sierra Pappa 0 Reputation points

2026-08-03T19:03:50.0833333+00:00

Looks like the dummy alias I used as an example was obfuscated.

I mean example123[plus symbol] [at] hotmail.com

Answer 1

Victor1-V 11,845 Microsoft External Staff Moderator

Hi Sierra Pappa,

I understand that some messages sent to your Hotmail account using plus addressing, such as account+tag at hotmail.com, do not appear in Outlook.com, even though the CRM marks them as delivered.

Please note that this is a user-to-user forum, so contributors cannot inspect the Outlook.com mail flow or your CRM delivery logs. To narrow this down, please try the following:

Send the same test message to your normal Hotmail address and to a new plus-addressed version. This can help determine whether only plus-addressed messages are affected.
In Outlook.com, check Other, Archive, Deleted Items, and Junk Email, then review Settings > Mail > Rules, Forwarding, and Junk email for anything that could move or block the messages.
Check Settings > General > Storage, because a full Microsoft cloud storage or mailbox can prevent new messages from being received.
Add the CRM sender address or domain under Settings > Mail > Junk email > Safe senders and domains, then repeat the test.

These checks are covered in Can't send or receive email in Outlook.com.

If the base address receives the CRM message but the plus-addressed version does not, contact Outlook.com Support from Help in Outlook.com, enter the issue, and scroll down the page until you see "Still need help?", click Yes. Include the sender address, recipient address, date and time with time zone, and the CRM message or delivery ID. Because the messages originate from your application, also check the delivery details through Sender Support in Outlook.com. Sender filtering can consider the sending IP, domain, authentication, reputation, complaint rate, and message content, even when SPF, DKIM, and DMARC are configured.

For your privacy, please do not post personal information, such as full email addresses, passwords, verification codes, message IDs, IP addresses, or email headers.

I hope the comparison test helps identify whether the missing messages are specific to plus addressing or to the CRM sender.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Victor1-V 11,845 Reputation points Microsoft External Staff Moderator

2026-08-05T14:28:59.3333333+00:00

I hope you are doing well, Sierra!

I'm following up to check if you've had a chance to look over my reply.

Please feel free let me know if you need any further assistance. I look forward to hearing back from you.
Sierra Pappa 0 Reputation points

2026-08-05T14:35:16.42+00:00

Thanks for following up.

Strangely, what happened is that the missing email dropped into my inbox 24 hours late and then when I've tested another email send, it's dropped in straight away. Sob ndokt know of this was a glitch but this was just one +tag email. There are others that were sent days ago that haven't pulled through.

I've not yet tried the the other tests mentioned.
Victor1-V 11,845 Reputation points Microsoft External Staff Moderator

2026-08-06T13:45:36.7633333+00:00
Thank you for the update. The immediate arrival of one +tag message confirms that the address format can receive mail, but it does not explain why other messages are delayed or missing.

Please complete the comparison test by sending the same message from the same sender to both the standard address and a +tag address. Also check Other, Junk Email, rules, forwarding, and mailbox storage. These are the recommended checks for missing Outlook.com messages.

If the CRM messages remain affected, ask the CRM provider to review its delivery logs and follow Outlook.com Sender Support. Sender filtering considers factors beyond SPF, DKIM, and DMARC.

If some messages are still arriving late or not at all, you may also want to contact Outlook.com Support:

Go to Outlook.com and sign in.

Select the Help icon, the question mark, in the upper-right corner.

In the Help pane that opens, search for "email management", then press Enter.

Scroll down the page until you see "Still need help?", click Yes.

Choose "Chat with a support agent in your web browser."

Review the issue description and confirm an email address you can access.

Click Confirm to create the service request. The screen will indicate that your request has been submitted and the system is connecting you to Outlook.com live chat support, which may take a moment to load.

I hope this helps identify whether the issue is tied to a particular sender or a broader Outlook.com delivery issue.