I need to white list outr email server IP

Question

I need to white list outr email server IP

Ante Kotarac 40

I'm working on project where we have our own email server, it is connected in rerouting schema with exchange online using outbound/inbound connectors.
When client sends email to over 380 recipients, we are getting error "too many recipients".

Settings in exchange 'Recipients limit' is set to 500, but only 380 are processed.

Our clients are complaining, we need help with this.

Any suggestions here would be much appreciated.

Thank you in advance.

Anonymous

2024-04-29T07:39:54.73+00:00

Hi，

Thanks for posting your question in the Microsoft Q&A forum.

“ I'm working on project where we have our own email server, it is connected in rerouting schema with exchange online using outbound/inbound connectors.” Did you mean that your email server send the message to EXO via dedicated connectors? And did you use Exchange Server? Is the EXO also yours? Please help provide the full NDR so that we could know where is the limit.
Anonymous

2024-05-02T05:17:46.73+00:00

Hello, it's been a long time since I've heard from you, did my previous reply help you, if it was useful, you can mark it as an answer. Thank you for your understanding and support.

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Anonymous

2024-04-29T07:39:54.73+00:00

Hi，

Thanks for posting your question in the Microsoft Q&A forum.

“ I'm working on project where we have our own email server, it is connected in rerouting schema with exchange online using outbound/inbound connectors.” Did you mean that your email server send the message to EXO via dedicated connectors? And did you use Exchange Server? Is the EXO also yours? Please help provide the full NDR so that we could know where is the limit.
Anonymous

2024-05-02T05:17:46.73+00:00

Hello, it's been a long time since I've heard from you, did my previous reply help you, if it was useful, you can mark it as an answer. Thank you for your understanding and support.

Answer 1

Ante Kotarac 40

Hi, sorry for late response, had a busy week.

We have customers to whom we provide email update service, they use exchange online.

We connect to their online exchange our mail server that does processing (Mail Flow - Connectors - Outbound/Inbound).

So, based on configuration some emails are re-routed to/from our email server.

This fails when there are more then 380 recipients.

Thank you in advance for any help, Ante

Anonymous

2024-05-03T09:43:03.7266667+00:00
I'm glad to hear from you.

Based on your description, I confirm some issues with you.

“Some emails are re-routed to/from our email server.” I understand that all the emails from this Exchange Online organization will send to your mail server, and all the emails to this organization will achieve your mail server first. If yes, is your email system Exchange Server? And what is version of Exchange server?

You can use the Get-SendConnector " YourConnectorName " | Format-List cmdlet command to view the connector details.

Please help provide the full NDR or error message as I mentioned before.
Ante Kotarac 40 Reputation points

2024-05-07T06:24:23.9933333+00:00
Hi again,

We have our own smtp server (hosted in azure) we don't use exchange.

3 . I can not provide full document in public, for confidentiality reasons.
But I can give you more interesting part without client data.
This is response part

"response":"452 4.5.3 Too many recipients [FR1PEPF00000F10.DEUP281.PROD.OUTLOOK.COM 2024-05-06T05:41:20.732Z 08DC667060C27C65]","responseCode":452,"command":"RCPT TO"

This happens when our smtp server sends back email to exchange online, part of emails goes correctly and some number returns with this error.

Thank you in advance.

Best Regards, Ante
Anonymous

2024-05-08T08:03:20.1566667+00:00

Hi，@Ante Kotarac

It's nice to hear back from you.

According to “ FR1PEPF00000F10.DEUP281.PROD.OUTLOOK.COM” of the error message ， it seems that this error is generated by Azure side. This issue occurred when your SMTP server send message to EXO, if the error generated by Azure, it means this message didn’t reach EXO. It is recommended to check the configurations of your SMTP server.

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I need to white list outr email server IP

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