If the file size is too large, Outlook Express will be unable to attach the file or send the email to the recipients. Several file compression tools such as Winzip, Winrar etc. are available for free on the internet and can be used to compress files to reduce their size before attaching them to an email. Alternatively, Microsoft Outlook Express provides an option to cut attachments that exceed a stipulated size to multiple smaller sized emails automatically. The option to split large messages can be enabled from the "split messages higher than" Advanced option in the Accounts Menu of the Outlook Express email application.
It may happen that when uploading files as attachments under Outlook Express, it takes a long time and in the end the email doesn't even get sent out. This may be due to the size of the file being too large.
To be able to send your files, you can opt to send them under different files attachment or through separate emails.
The first solution consists of compressing the files into several ZIP files using your usual tools (WinZip, 7-Zip, PowerArchiver, Winrar, etc.).
Otherwise, Microsoft Outlook Express has a feature to automate the cutting attachments too large.
However Microsoft outlook Express has an option that automatically cuts attachments that are too large.
To enable this option:
Click on Tools and select Accounts
Select the email accounts
Click on Advanced and check the option Split messages higher than