Body property is just a wrapper around Filename
property. This means that whenever you access Body
propertywodSmtpServer will internally access file specified
in Filename property, and read or write it for you. This is
very neat feature that can be used for smaller messages.
But, if message is much larger (more than few hundred
kb's) you should consider accessing file on disk
directly.
If Filename property is not specified or is empty
string, wodSmtpServer will create temporary file for you,
and read and write to it instead of you. You don't have
to delete such file manually, because wodSmtpServer will
automatically delete it when message object is destroyed
(if for some reason your application generates GPF they
will probably not be deleted).