Error "<#5.5.2 smtp;554 5.5.2 Invalid data in message> #SMTP#" when you send attachment in your mail

Some users were receiving error <#5.5.2 smtp;554 5.5.2 Invalid data in message> #SMTP# when they sent message with attachment.

The problem is when attached document name is longer than 50 characters. Some Firewalls have header size restriction and that limit blocks this messages to be sent.

To correct this, change header limit on affected Firewall or shorten the name of the document you are sending (which is probably not good permanent solution).

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Update #1: Default header size limit in Exchange 2007 is 64K.

Update #2: It might be the SMTP version problem. Mail is rejected with CONTENT-DISPOSITION error (overly long message header field for CONTENT-DISPOSITION) but not for all SMTP servers (same mail sent through different SMTP servers). If you send mail with attachment that has name longer than 50 characters from Exchange 2007 directly through DNS you may encounter this error, but if you send same mail from Exchange 2007 through smart host (other than Exchange) mail is delivered with no errors (possible workaround).

Update #3: There is a good article on Symantec's web site about parameters in Config.cf file. Check SMTP block/unblock possibilities.
Article:
http://service1.symantec.com/SUPPORT/ent-gate.nsf/pfdocs/2002031311321154?OpenDocument&ExpandSection=13%2C8

Update #4: Anonymous (*send me your name*) left a comment below regarding reasons for this error message:
"We found this was simply a matter that the message was created in Outlook "rich text" format (which embeds attachments into the message body) instead of plain text or HTML which creates attachments normally"

Administering offline address book in Outlook 2003 and Outlook 2007

There is a good article regarding Offline Address Book (OAB) on Microsoft's support site.

From article's summary:

Microsoft Office Outlook 2007 and Microsoft Office Outlook 2003 have many new features and enhancements that are related to the offline address book. By default, Outlook uses a cached mode configuration. Because cached mode generates an offline address book, understanding how to configure the offline address book so that it works efficiently in your Microsoft Exchange organization is important.

Article can be found here.

Update rollup 2 for Exchange 2007 is now available

Microsoft released new update rollup for Exchange Server 2007 on 5th of May. This update is cummulative update and includes Update rollup 1. Update can be downloaded from Microsoft Update (not Windows Update), which includes Exchange patches or downlload it from KB935490.

Check known issues section of KB article http://support.microsoft.com/?kbid=935490 before applying this update.

Outlook Web Access (OWA) implementation in mixed Exchange 2007 and Exchange 2000/2003 environment

Microsoft documentation about transition to Exchange 2007 suggests that you should install HUB Transport and Client Access (CAS) roles first and than mailbox server role. Exchange 2007 installation order in transition should look like this:

• Client Access server role
• Hub Transport server role
• Mailbox server role
• Unified Messaging server role

Exchange 2007 CAS role enables users to gain access to their mailboxes through web browser (OWA), ActiveSync or Outlook Anywhere (fromerly known as RPC over HTTPS). It is actually "replacement" for Exchange Front-End server known from previous versions.

Microsoft suggests that you should replace Front-end servers with Exchange 2007 CAS (I think it would be best to say redirect users to new Exchange CAS. Redirection process can be done on FW or just as a change in DNS, but this depends on your network configuration) prior mailbox move from Exchange 2000/2003 to Exchange 2007 mailbox server.

Since new Exchange 2007 OWA is using /owa(https://whatever.yourdomain.com/owa) as virtual directory name, redirection is done automatically if you open https://whatever.yourdomain.com/exchange in your web browser.

Choice whether you will be redirected to Exchange 2007 OWA or Exchange 2000/2003 OWA is based on your mailbox storage location. This means that if your mailbox resides on Exchange 2003 server you will see Exchange 2003 OWA look-and-feel, and if your mailbox resides on Exchange 2007 mailbox server you will see Exchange 2007 OWA look-and-feel. This process is done automatically and the only request is that primary point for OWA is Exchange 2007 CAS server.

So if you access https://whatever.yourdomain.com/exchange...

... OWA 2007 screen will be shown on the page and if your mailbox store is on Exchange 2003 server....

...you will see Exchange 2003 look-and-feel.

Note:
Don't forget to import SSL certificate from your Exchange 2000/2003 server to your new Exchange 2007 Client Access Server (or servers).

Related articles:
http://msexchangeteam.com/archive/2007/02/07/434523.aspx
http://technet.microsoft.com/en-us/library/aa997610.aspx

Ports that need to be open on Firewall for Edge Transport servers

Ports that need to be open on firewall for Edge Server subscription with Hub Server to function properly:

For Inbound traffic:
SMTP - TCP port 25 (from Internet)
SMTP - TCP port 25 (from Edge server to Hub server on internal network)
For Outbound traffic:
SMTP - TCP/UDP port 25 (from Edge to Internet)
SMTP - TCP/UDP port 25 (from Hub to Edge server)
LDAP for EdgeSync - TCP port 50389 (from Hub to Edge server) Secure LDAP for EdgeSync - TCP port 50636 (from Hub to Edge server)

Since Edge server needs to communicate with Hub server it is important that it can resolve Hub transport servers by FQDN and Hub transport servers must be able to resolve Edge servers by its FQDNs.

To accomplish this you need to either open 53 (DNS) port and configure internal network adapter to use internal DNS but as a security precaution I would suggest to enter DNS records for Edge servers on local DNS manually and to fill hosts file on Edge servers with FQDNs for Hub transport servers.

Active Directory Application Mode (ADAM)

In order to install Exchange 2007 Edge server role you need to install Active Directory Application Mode (ADAM) on your computer if you do not have Windows 2003 R2 installed. You can download ADAM from this link.

ADAM is part of Windows 2003 R2 and you can find it in Control Panel --> Add/remove Windows Components

You do not need to create an ADAM instance by yourself for Exchange 2007 Edge server. ADAM instance will be created after you create Edge Subscription on Hub server.