whitelist [Moderator note: Personally Identifiable Information removed] this email or domain

Question

whitelist [Moderator note: Personally Identifiable Information removed] this email or domain

Brenda Holden 0

Need to whitelist either the email [Moderator note: Personally Identifiable Information removed] address

or the domain [Moderator note: Personally Identifiable Information removed]

This sends scanned documents from the backroom copier/scanned/printer to

various programed email addresses in the office.

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2 answers

Your answer

Answer 1

Jayden-P 2,600 Independent Advisor

Please note that this forum is a public platform, and moderators will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

Hi @Brenda Holden

Before provide further troubleshooting steps, could you help clarify a few details?

1/Is mc-copiers.net a domain owned and managed by your organization, or is it a third-party/vendor-managed domain?

2/Which recipient domain is rejecting or blocking the messages?

Outlook.com / Hotmail.com / Live.com
Your company's email domain
Another external domain

3/Are you receiving a bounce-back message or SMTP error? If so, please provide the full error.

4/I see the thread is tagged with Exchange Server. Is your organization using:

Exchange Server 2016/2019
Exchange Server Subscription Edition (SE)
Exchange Online (Microsoft 365)
Hybrid Exchange

Please provide more information so I can understand your situation better.

Brenda Holden 0 Reputation points

2026-08-14T18:00:27.0333333+00:00
It's a third party domain. We do not own or controll it.

The problem is with our company email address(es). It's an intermitten problem. Our addresses end in @balletmagnificat.com.

No error message just never receive the email(s). The third-party tech verifies that the email was sent by the copy machine.

We use Microsoft365 email server.

I want to whitelist the address ([Moderator note: Personally Identifiable Information removed]) on the server. I have admin privileges and created a Connector for mc-copiers.net in the Exchange Admin Center. Should this (in effect) whitelist it for all of our email addresses or do I need to whitelist it as a SafeSender on each individual PC?
Jayden-P 2,600 Reputation points Independent Advisor

2026-08-14T18:10:25.41+00:00
Creating a connector for mc-copiers.net does not automatically whitelist the domain for all users. Connectors are primarily used for mail routing and establishing trust between mail systems. They do not function as a tenant-wide Safe Sender list.

Since mc-copiers.net is a third-party domain and you're using Microsoft 365, I recommend two actions:

Ask the vendor/sender to verify their email configuration, including:

SPF records

DKIM signing

DMARC policy

Sending IP reputation

Intermittent delivery issues can occur when email authentication is not configured correctly or when some sending servers have a poor reputation.

Add mc-copiers.net to the Microsoft 365 Tenant Allow List. This applies at the tenant level and is preferable to configuring Safe Senders on individual Outlook clients. Manage allows and blocks in the Tenant Allow/Block List - Microsoft Defender for Office 365 | Micros…

Safe Sender entries are user-specific and mainly affect Outlook's junk email filtering. They do not guarantee delivery if Microsoft 365 blocks or filters the message before it reaches the mailbox.

If the issue persists after adding the allow entry, run a Message Trace for a missing email to determine whether Microsoft 365 is receiving the message and what action is being taken on it.
Jayden-P 2,600 Reputation points Independent Advisor

2026-08-15T15:16:25.38+00:00

Hi @Brenda Holden

Have you checked the provided answer? Any update would be great.
Brenda Holden 0 Reputation points

2026-08-19T01:38:16.3933333+00:00

I've added the connector and 'allowed tenant'. Feel like I'm using a shotgun.

Also am having the affected account check the programed email addresses in the copier as she reports it is also intermittent with some of the other accounts (on other PCS). I'm in a wait & see mode until they try to scan & email to their accounts.
Jayden-P 2,600 Reputation points Independent Advisor

2026-08-19T07:57:14.0433333+00:00

At this point, monitoring for the next occurrence and gathering more data is probably the best approach. If you have any other updates or new information, please feel free to reach out.

Answer 2

To allow messages from that copier sender or domain in Outlook, add the specific address or the domain to the Safe Senders list.

For Outlook on the web:

Select Settings.
Go to Mail > Junk email.
Under Safe senders and domains, select Add safe sender.
Add either:
- the full sender address, or
- mc-copiers.net to trust the whole domain.
Select OK, then Save.

For classic Outlook:

On the Home tab, in the Delete group, select Junk > Junk E-mail Options.
Open the Safe Senders tab.
Select Add.
Enter the full email address or the domain.
Select OK.

If the mailbox is hosted on Exchange or Exchange Online, Outlook Safe Senders changes might not be recognized by the server. In that case, messages can still end up in Junk Email, and administrator assistance may be required.

For devices such as copiers or scanners that send mail through Microsoft 365 or Office 365, supported sending methods include Client SMTP submission, SMTP relay, Direct Send, and High Volume Email.