Trouble sending large files to a email group but can to the individuals in that group

[usatraveler]

Operating system::    Windows 11 23H2
Outlook version:     18429.20158
Email type or host:    Exchange Online

---

I have a user that just updated his office (Microsoft 365) to the latest version. Version 2501 (Build 18429.20158 Click to Run)
He used to be able to send emails with large attachments to a group email (all internal emails) that he had setup but now he is getting an error when he sends large attachments to the same group. If he goes ahead and expands the group so it list all the individual emails then he can send the email with the large attachments no problem.

This what he is getting now and it used to work. I have all the users setup allowing them to send and receive 150 mb file attachments.

KICK OFF PROJECT (XXXXXXXXXPROJECTKICKOFF@xxxxxxxxsystems.com)
Your message is too large to send. To send it, make the message smaller, for example, by removing attachments.

The maximum message size that's allowed is 36 MB. This message is 83 MB.

 

[Diane Poremsky]

The maximum message size that's allowed is 36 MB.

So this message is in error? Are all recipients within the some domain?

 

[usatraveler]

So this message is in error? Are all recipients within the some domain?

So this message is in error? Are all recipients within the some domain?

Yes they are all on the same domain. I wanted to double check because we have another division that has a different domain but all the emails in this group are all on the same domain.

 

[usatraveler]

I can't see where a update to Outlook would have made this happen unless there is a change I need to make it allow for big attachments in a group name.

 

[Diane Poremsky]

As an FYI - if the other division is in the same Microsoft tenant as this, it shouldn't be a problem as it doesn't leave the tenant.

I just checked - no, DLs don't have limits, only mailboxes -

You've ran this PowerShell to check all the mailboxes?
$mb= Get-Mailbox -ResultSize unlimited; $mb | where {$_.RecipientTypeDetails -eq 'UserMailbox'} | Format-Table Name,MaxReceiveSize,MaxSendSize,RecipientLimits

or this to get resource, shared mailboxes etc. too.
$mb= Get-Mailbox -ResultSize unlimited; $mb | Format-Table Name,MaxReceiveSize,MaxSendSize,RecipientLimits

 

[usatraveler]

Thank You Diane for that information I have not run these scripts but I will and see what they show. I had manually gone through the mailboxes and checked them individually from the gui interface. I will check them and let you know what I find out.

 

[usatraveler]

Diane, I ran the scripts and most of the mailboxes show 150 but some are at 75 and they are not the normal names for mailboxes. Is there a script that will allow me to change them all to 150?

 

[usatraveler]

Diane, Doing some more searching and I am seeing the group that is having issues is not in the Distribution list but under Microsoft 365. I am including a screen grab and maybe that has something to do with it. Thanks again for your knowledge and help.

 

[Diane Poremsky]

If the email is not in the dl then it should not be the cause.

Set-mailbox

Set-Mailbox (ExchangePowerShell)

You can use this cmdlet for one mailbox at a time. To perform bulk management, you can pipeline the output of various Get- cmdlets (for example, the Get-Mailbox or Get-User cmdlets) and configure several mailboxes in a single-line command. You can also use the Set-Mailbox cmdlet in scripts. You...

learn.microsoft.com

Set-Mailbox -Identity "display name or email address" --MaxSendSize 150MB

Size limits -

Configure message size limits for a mailbox

Summary: How to use the Exchange admin center (EAC) and the Exchange Management Shell to set message size limits for a user mailbox.

learn.microsoft.com