Exchange 2010 Message Size limits

[irbk]

Ok, I know there has to be info on the web some where, but I've spent the last 90 min searching for this information and can't come up with anything. Have a co-existence environment right now with Exchange 2003 and Exchange 2010. All my users are on the Exchange 2010 environment. We want to allow up to 20mb of attachments (incoming and outgoing both internal and external).
I can send a 16mb test message internal just fine, so my internal limits seem to be ok. However, when I try to send a 10mb file to my yahoo account, I get a kick back from my server saying "This message is larger than the size limit for messages. Please make it smaller and try again." and the "Diagnostic information for administrators" says that the generating server is my Exchange 2010 server and the Message size exceeds fixed maximum message size.
Here is where I've looked.
1. EMC - Org Config - Hub Transport - Global Settings - Transport Settings - Properties.
The transport limits for send and receive are set at 20480(kb).
2. EMC - Org Config - Hub Transport - Transport Rules (no rules defined here)
3. EMC - Org Config - Hub Transport - Send Connectors - Internet Mail Connector - Properties
No Maximum size limit is set.
4. EMC - Server Config - Hub Transport - Receive Connectors - Properties
Maximum message size is set at 20480(kb) for both the default connector and client connector.
5. At the user level, I've verified that no specific setting is defined, so that the system defaults should be used.
6. From the EMS I ran get-transportconfig and this is what is shown

ClearCategories                                      : True
DSNConversionMode                                    : UseExchangeDSNs
ExternalDelayDsnEnabled                              : True
ExternalDsnDefaultLanguage                           :
ExternalDsnLanguageDetectionEnabled                  : True
ExternalDsnMaxMessageAttachSize                      : 10 MB (10,485,760 bytes)
ExternalDsnReportingAuthority                        :
ExternalDsnSendHtml                                  : True
ExternalPostmasterAddress                            :
GenerateCopyOfDSNFor                                 : {}
HygieneSuite                                         : Standard
InternalDelayDsnEnabled                              : True
InternalDsnDefaultLanguage                           :
InternalDsnLanguageDetectionEnabled                  : True
InternalDsnMaxMessageAttachSize                      : 10 MB (10,485,760 bytes)
InternalDsnReportingAuthority                        :
InternalDsnSendHtml                                  : True
InternalSMTPServers                                  : {}
JournalingReportNdrTo                                : <>
MaxDumpsterSizePerDatabase                           : 18 MB (18,874,368 bytes)
MaxDumpsterTime                                      : 7.00:00:00
MaxReceiveSize                                       : 20 MB (20,971,520 bytes)
MaxRecipientEnvelopeLimit                            : 5000
MaxSendSize                                          : 20 MB (20,971,520 bytes)
MigrationEnabled                                     : False
OpenDomainRoutingEnabled                             : False
Rfc2231EncodingEnabled                               : False
ShadowHeartbeatRetryCount                            : 3
ShadowHeartbeatTimeoutInterval                       : 00:05:00
ShadowMessageAutoDiscardInterval                     : 2.00:00:00
ShadowRedundancyEnabled                              : True
OrganizationRelationshipForExternalOrganizationEmail :
SupervisionTags                                      : {Reject, Allow}
TLSReceiveDomainSecureList                           : {}
TLSSendDomainSecureList                              : {}
VerifySecureSubmitEnabled                            : False
VoicemailJournalingEnabled                           : True
HeaderPromotionModeSetting                           : NoCreate
Xexch50Enabled                                       : True

I thought perhaps it might have something to do with the ExternalDsnMaxMessageAttachSize being at 10mb, but as I said earlier, I can send a 16mb message internally and the InternalDsnMaxMessageAttachSize is set to the same 10mb, so I don't think that is it.
7. I've checked my Exchange 2003 server limits and made sure they were also set to 20480(kb) as well as made sure there was no limit on the connector size in Exchange 2003.

I'm hoping some one might be able to provide me with some ideas as to where the limit is coming from.

Thanks in advance.

 

[58sniper]

http://technet.microsoft.com/en-us/library/bb124345(EXCHG.80).aspx

These should help you narrow it down. Depending on your environment, some of these might come back with no results.

Get-ForeignConnector | fl Name,MaxMessageSize
Get-SendConnector | fl Name,MaxMessageSize
Get-ReceiveConnector | fl Name,MaxMessageSize
Get-ADSiteLink | fl Name,MaxMessageSize
Get-RoutingGroupConnector | fl Name,MaxMessageSize
Get-TransportConfig | fl MaxSendSize,MaxReceiveSize
Get-DistributionGroup | fl name,MaxSendSize,MaxReceiveSize
Get-DynamicDistributionGroup | fl name,MaxSendSize,MaxReceiveSize
Get-Mailbox | fl name,MaxSendSize,MaxReceiveSize
Get-MailContact | fl name,MaxSendSize,MaxReceiveSize
Get-MailPublicFolder | fl name,MaxSendSize,MaxReceiveSize
Get-MailUser | fl name,MaxSendSize,MaxReceiveSize

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[58sniper]

I should add that some of those might not pertain to sending to Yahoo. But they can all have size limits.

I'm assuming, also, that mail is going right out from the 2010 side, and not through some RGC back to the 2003 side?

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[irbk]

Get-ForeignConnector | fl Name,MaxMessageSize - Returns nothing (an exchange 2007 command that doesn't work in 2010?)

Get-SendConnector | fl Name,MaxMessageSize - Returns "unlimited"

Get-ReceiveConnector | fl Name,MaxMessageSize - Returns 20Mb (as shown in the get-transportconfig above)

Get-ADSiteLink | fl Name,MaxMessageSize - Returns "unlimited" for all the sites

Get-RoutingGroupConnector | fl Name,MaxMessageSize - Returns "unlimited" (as I stated above)

Get-TransportConfig | fl MaxSendSize,MaxReceiveSize - Returns 20Mb (as shown above in the get-transportconfig)

Get-DistributionGroup | fl name,MaxSendSize,MaxReceiveSize - Returns "unlimited" for all my distro groups

Get-DynamicDistributionGroup | fl name,MaxSendSize,MaxReceiveSize - Returns nothing (an exchange 2007 command that doesn't work in 2010?)

Get-Mailbox | fl name,MaxSendSize,MaxReceiveSize - Returns all my users with settings of "unlimited"

Get-MailContact | fl name,MaxSendSize,MaxReceiveSize - Returns contacts with settings of "unlimited"

Get-MailPublicFolder | fl name,MaxSendSize,MaxReceiveSize - Returns all my public folders with settings of "unlimited"

Get-MailUser | fl name,MaxSendSize,MaxReceiveSize - Returns mail enabled user with settings of "unlimited"

So, I'm stumped. Everything that should be 20Mb is 20mb but I still can't send over ~10Mb externally.

 

[irbk]

I'm not 100% sure, but I believe you are correct, mail is going right out the 2010 side, not back through the 2003 server.

 

[58sniper]

The ones that return nothing just mean you don't have those (foreign connectors, DDGs, etc)

Okay - we need to verify that. Send an email from the same mailbox to an outside target, and look at it in Message Tracking, or look at the headers on the target. Let's make sure we don't have to look at the 2003 side as being at play here. We'll figure it out.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[irbk]

Here is the header of the message (cleaned for my protection)

X-Apparently-To:   myaddress@yahoo.com via 209.191.85.7; Tue, 09 Mar 2010 13:34:38 -0800 
Return-Path:   <me@mydomain.com> 
X-YMailISG: <really silly long string that I don't think is necessary>
X-Originating-IP:   [my_proofpoint box ip] 
Authentication-Results:   mta113.mail.sp2.yahoo.com from=; domainkeys=neutral (no sig); from=mydomain.com; dkim=neutral (no sig) 
Received:   from 127.0.0.1 (EHLO my_proofpoint.mydomain.com) (my_proofpoint_IP) by mta113.mail.sp2.yahoo.com with SMTP; Tue, 09 Mar 2010 13:34:38 -0800 
Received:   from mail.mydomain.com (exchange2003.mydomain.com [Exchange2003_IP]) by My_proofpoint(8.14.3/8.14.3) with ESMTP id o29LYawM030831 for <me@yahoo.com>; Tue, 9 Mar 2010 15:34:36 -0600 
Received:   from Exchange2010.mydomain.com ([Exchange2010_IP]) by mail.mydomain.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 9 Mar 2010 15:34:36 -0600 
Received:   from Exchange2010.mydomain.com ([::1]) by Exchange2010.mydomain.com ([::1]) with mapi; Tue, 9 Mar 2010 15:34:36 -0600 
From:   Kirby Timm <me@mydomain.com>  Add sender to Contacts 
To:   "me@yahoo.com" <me@yahoo.com> 
Subject:   Test 11 
Thread-Topic:   Test 11 
Thread-Index:   Acq/0FBM5peMhKrwRyaTFS5HbLGG5g== 
Date:   Tue, 9 Mar 2010 21:34:35 +0000 
Message-ID:   <9083801713DBE84597F7B928894BB45D0142C440@Exchange2010.mydomain.com> 
Accept-Language:   en-US 
Content-Language:   en-US 
X-MS-Has-Attach:    
X-MS-TNEF-Correlator:    
Content-Type:   multipart/alternative; boundary="_000_9083801713DBE84597F7B928894BB45D0142C440MailServertnama_" 
MIME-Version:   1.0 
X-OriginalArrivalTime:   09 Mar 2010 21:34:36.0717 (UTC) FILETIME=[5109A5D0:01CABFD0] 
X-Proofpoint-Virus-Version:   vendor=fsecure engine=1.12.8161:2.4.5,1.2.40,4.0.166 definitions=2010-03-09_13:2010-02-06,2010-03-09,2010-03-09 signatures=0 
X-Proofpoint-Spam-Details:   rule=notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-0908210000 definitions=main-1003090200 
Content-Length:   1920

So, assuming I'm reading this correctly, it does look like my 2010 box is sending it to my 2003 box, then to our proofpoint box, and out to yahoo. Would you agree?

 

[irbk]

Just for giggles, I shut down the Exchange 2003 services on the old Exchange box and sent myself a test message. I was able to get it at my yahoo account. So I believe this should prove that mail is flowing directly out of my 2010 server to the 'net.

 

[58sniper]

And did you try sending yourself a large attachment when the 2003 box was off?

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[irbk]

Yes I did and it still didn't work.

 

[irbk]

I do believe I found the solution.... though it makes 0 sense.
I found on my 2003 box, that in the Default SMTP Virtual Server connection, there was a 10Mb limit. I removed that limit, and now I can send yahoo a 10Mb attachment (which some how in going from my server to yahoo turned into a 14mb message, but that's neither here or there). So now I'm really confused. Apparently this limit in the Default STMP Virtual Server on the 2003 box was not allowing messages over 10Mb, yet when the exchange services on the 2003 box were shut down, messages still flowed in/out and the limit was still imposed. So The solution is found I guess. Not sure why it's the solution but it works now.
Now I need to find out how to best decommission the exchange 2003 server.

 

[58sniper]

(which some how in going from my server to yahoo turned into a 14mb message, but that's neither here or there).

That's MIME encoding bloat. That can cause attachments to be up to 40% bigger.

For the decommissioning part, see

http://technet.microsoft.com/en-us/library/bb288905(EXCHG.80).aspx

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[irbk]

Thanks for the link, I'd found the same thing after a search. Not ready to decommission just yet.