Outbound attachment over 1MB fail

[will136]

Hi - running exchange 2003 on W2K3 SP2. I have no size limits set but cannot send outbound mail with attachment of 1MB or more.
However there are a few caveats:

1) Can send large attachments to gmail
2) Can send to an org using exchange if they are using message1 (etc) as a host.

I'm new to this system and note it's configured with no smart host.

I've ran Best Practices analyser and Troubleshooting assistant and no red flags. I do get some DCOM and transport errors :

Event Type: Error
Event Source: MSExchangeTransport
Event Category: SMTP Protocol
Event ID: 7004
Date: 7/30/2009
Time: 12:43:43 PM
User: N/A
Computer: M3
Description:
This is an SMTP protocol error log for virtual server ID 1, connection #3566. The remote host "72.5.61.170", responded to the SMTP command "xexch50" with "504 Need to authenticate first ". The full command sent was "XEXCH50 2488 2 ". This will probably cause the connection to fail.

plus

Event Type: Error
Event Source: MSExchangeTransport
Event Category: Routing Engine/Service
Event ID: 929
Date: 7/30/2009
Time: 12:31:53 PM
User: N/A
Computer: xx
Description:
Failed in reading Connector's DS Info Process Id: 1488 Process location: C:\WINDOWS\system32\inetsrv\inetinfo.exe ConnectorDN: CN=FPCon(xx),CN=Connections,CN=xxxx,CN=Routing Groups,CN=xxxx,CN=Administrative Groups,CN=xxxxxxxxxx,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=pcyc,DC=com Hr:c004038a Attribute:

Any help would be much appreciated.

Thanks!

 

[theravager]

Sizes are generally calculated on the attachment after its encoded, not the binary size prior to attachment.

Ie a 1m Zip file can be like 10m depending on what it is

 

[58sniper]

MIME conversion can increase a file by up to 30-40%. You have to account for that.

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/

 

[Zelandakh]

How do you know you cannot send above 1MB? Do you get an error email coming back?

 

[will136]

Appreciate the responses.
I'm sending a .bmp file as a test attachment.
There are no limits set on the system yet I cannot send more than ~ 1MB attachment.
Messages get stuck in the outbound queue till they time out.
Could not find anything relevant at the ucblogs link.

 

[58sniper]

Where have you looked for size settings in Exchange? There are at least 8 places where limits can be defined.

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/