Block large attachments on the client (not the Exchange server)

[Craig]

Hi,

Does anyone know a method of blocking users attach files over a certain size
to a message in Outlook?

I know the message size can be configured in Exchange however I am looking
for a client based solution as I don't have control over the Exchange server
settings which is currently set too large at 30mb.

I would like to prevent users from composing new emails which are over 15mb
without touching Exchange, so it needs to be a client side Outlook addin or
setting.

Any help would be appreciated.

Thanks

Craig

 

[Peter Foldes]

Set a rule that looks something like the following.

Any email larger then ????? KB or MB

 

[Diane Poremsky [MVP]]

You'll need to use VBA to catch them.
http://www.slipstick.com/mail1/lgmail.asp

rather than pop up the warning and allow the sender ot continue, change the
code to cancel the send.

--
Diane Poremsky [MVP - Outlook]

Outlook & Exchange Solutions Center: http://www.slipstick.com/

Outlook Tips by email:
mailto:[email protected]

EMO - a weekly newsletter about Outlook and Exchange:
mailto:[email protected]

Poll: What version of Outlook do you use?
http://forums.slipstick.com/showthread.php?t=27072

 

[VanguardLH]

Set a rule that looks something like the following.

Any email larger then ????? KB or MB

The problem with defining an outbound rule is that it gets exercised AFTER
sending the e-mail. Notice the syntax of a new outbound rule says:

Check messages after sending

The "after" behavior means the rule won't *block* the send of overly large
e-mails. Also, for outbound rules, the only "size" clause you can add is:

with a size <in a specified range>

The problem with that clause is that you have to define a range. You cannot
define a lower limit or threshold beyond which the rule will fire. You want
the rule to fire when the e-mail is over 15000 KB in size but you cannot
just set the "at least" field to that value. Outlook demands that you also
define an upper limit although that is irrelevant in the test that you want
to perform. So you have to use:

at least = 15000 (KB)
at most = 999999 (KB)

Well, think about it. That means the rule won't fire if the e-mail exceeds
999,999 KB (1 TB - 1 KB). That the user's mail server is unlikely to accept
a 1 TB e-mail doesn't mean the user won't try to send one, and Outlook's
rule won't fire. However, this is much less an issue than the fact that
outbound rules fire AFTER the sending mail session has ended so it would be
too late to stop the sending of that overly large e-mail.

For an outbound rule, there is no "do not send" clause. This is true for
Outlook 2003 and earlier versions. Does Outlook 2007 have a more robust
rules set where a "do not send" clause or its equivalent was added for
outbound rules?

The best that I can see for an outbound rule might be something like:

Check messages after sending
with a size at least 15000 and at most 999999 kilobytes
defer delivery by 120 minutes (the max value allowed)
and perform a <custom action>
and stop processing more rules

The custom action would be a macro that alert the user that they sent a
message that exceed the configured "at least" threshold and to delete the
pending deferred e-mail. However, since you'll be into defining a macro to
create a custom action from which you can select for use in this rule, you
might as well as go with Diane's suggestion of using a macro that
interrogates the size of your outbound e-mails (but BEFORE they get sent).

 

[VanguardLH]

You'll need to use VBA to catch them.
http://www.slipstick.com/mail1/lgmail.asp

rather than pop up the warning and allow the sender ot continue, change the
code to cancel the send.

Question: Since you are adding a macro, and because of macro security,
wouldn't you want to digitally sign your code to eliminate the security
warning (and to avoid having to trust all unsigned macros from any source)?

http://www.howto-outlook.com/howto/selfcert.htm

 

[VanguardLH]

Hi,

Does anyone know a method of blocking users attach files over a certain size
to a message in Outlook?

I know the message size can be configured in Exchange however I am looking
for a client based solution as I don't have control over the Exchange server
settings which is currently set too large at 30mb.

I would like to prevent users from composing new emails which are over 15mb
without touching Exchange, so it needs to be a client side Outlook addin or
setting.

Any help would be appreciated.

Thanks

Craig

What TYPE of attachments are these piggish users sending in their e-mails?
Will they compress a lot? If so, you might get away with using an add-on
that automatically compresses (zips up) the attachments to make the e-mail
size smaller. For example, BxAutoZip (available in a free version), can be
configured to automatically compress all attachments exceeding some
threshold in size into one .zip file. Of course, since this is an add-on
that adds a toolbar with the intention of cooperative use by the user, the
users of Outlook where you install the add-on could always reconfigure or
disable it. If the attachments are highly compressible then this might
alleviate your problem of the mail server's size limit exceeding your wants.
Not all e-mails will compress down to half their size (from the 30MB limit
down to your self-imposed 15MB limit) but reducing the size of the e-mail
should help.

If the mail server is configured for a maximum size of 30MB for an e-mail,
why do you care about some arbitrary 15MB limit? After all, you state that
you are not the admin of the Exchange server so you are also not involved in
dictating the traffic volume on the network, either. If your concern is
that your employees might send e-mails that exceed the per-message receiving
quota at some customer's mail server (i.e., the recipient cannot accept
e-mails that big) then the recipient's mail server will reject your
employee's e-mails and send back a DSN (disposition status notification)
e-mail telling them that their e-mail got rejected because it was too big.
The employee then gets feedback that they are being sloppy in trying to use
e-mail as a file transfer mechanism for which it wasn't designed. The
employee gets the feedback and will have to decide how to reform regarding
their e-mail habits.

 

[Diane Poremsky [MVP]]

Trusting all macros is not a good choice (and at least one security software
changes it to signed only), but the option to always ask works well if you
don't want to bother signing macros.

My preference is always be alerted if macros are installed, so I have it set
to always ask.

--
Diane Poremsky [MVP - Outlook]

Outlook & Exchange Solutions Center: http://www.slipstick.com/

Outlook Tips by email:
mailto:[email protected]

EMO - a weekly newsletter about Outlook and Exchange:
mailto:[email protected]

Poll: What version of Outlook do you use?
http://forums.slipstick.com/showthread.php?t=27072

 

[Ken Slovak - [MVP - Outlook]]

It also depends on how static your VBA project is. I play with VBA code all
the time and would have to re-sign constantly, a real PITA. So I go for
prompts too

 

[VanguardLH]

It also depends on how static your VBA project is. I play with VBA code all
the time and would have to re-sign constantly, a real PITA. So I go for
prompts too

I'm hoping that the OP is being offered solid code for the macro. They
shouldn't have to change anything within it but just following the
instructions on how to add the macro to Outlook. The user asking for a
solution doesn't really want to be involved with VBA, debugging, or getting
prompted repeatedly. However, going through the process to add the macro is
a bit scary for most Outlook users and having to go through the signing
process just exacerbates that process, yet I would never recommend always
trusting unsigned macros.

 

[Edward Juden]

Craig,
If you want to allow your users to send large attachments without going through Exchange, you could set up a corporate FTP server, and then have the users use an Outlook Add-in that will upload the files securely to that FTP server, and then send the email to the user as normal. This will free up your exchange server. Recipients do not have to use Outlook, they can use the File Part Assembler.
It will also support using Google Docs as storage. All file types/sizes are supported. You can get more information here: http://apps.snickitybit.com/products/AttachmentHandler/attachmenthandler.html

Thanks,
Eddie



Craig wrote:

Block large attachments on the client (not the Exchange server)
02-Dec-09

Hi,

Does anyone know a method of blocking users attach files over a certain size
to a message in Outlook?

I know the message size can be configured in Exchange however I am looking
for a client based solution as I do not have control over the Exchange server
settings which is currently set too large at 30mb.

I would like to prevent users from composing new emails which are over 15mb
without touching Exchange, so it needs to be a client side Outlook addin or
setting.

Any help would be appreciated.

Thanks

Craig

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