Thank you for the clarification.
If the receiving MX server is rejecting your messages, it is because the remote mail server operator has set a limit which is smaller than the size of the e-mail message that you are attempting to send.
Your client should contact the intended recipient and have them ask their e-mail system administrator if it is possible to increase the size of the message they can receive.
Alternately, if you can upgrade to SmarterMail 14.4 Enterprise, and take advantage of the ability to link a file directly from one of the new connected services.
Note that these must be enabled on a per domain, and per account basis.
Once enabled on the per domain, and per account basis, they must also be enabled and mapped by the individual e-mail account holder.
Once mapped and enabled, you can store your files in one of the services and then provide a direct link to the file from any of the linked services by selecting LINK FROM during the composition of a message:
which opens the following window:
Then select your source and file and embed the link.
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